The Family Tree of the Pterosauria 16 – The Cycnorhamphidae

Earlier we looked at the descendents of Scaphognathus that shrank through Ornithocephalus to begat Pterodactylus. Then, we followed another shrinkage through No. 6 that begat Germanodactylus. Two germanodactylids were basal to lineages that ultimately produced Tupuxuara and Pteranodon among others.

Pterosaur family tree

Figure 3. Click to enlarge. The pterosaur family tree.

Here we back up to Scaphognathus to retrieve the last branch of the Pterosauria, the one leading to Cycnorhamphus and the ornithocheirids culminating with Anhanguera and a host of others.

Cycnorhamphus, its sisters and predecessor taxa

Figure 1. Cycnorhamphus, its sisters and predecessor taxa

Start Small and Get Smaller
We begin this clade with a small Scaphognathus, the Maxberg specimen, No. 110 in the Wellnhofer (1975) catalog. It was originally considered a juvenile because it stood only as high as the hips of the holotype, No. 109 and it appeared to have the expected juvenile proportions. Actually it was a small adult as we learned earlier. Distinct from SMNS 59395 the skull of the Maxberg specimen had a relatively shorter, blunter skull and larger orbit. The teeth were more robust. The postorbital process of the jugal was vertical. The premaxillary teeth are not so reduced. The quadratojugal process of the jugal is reduced to a nub. The mandible appears to shallow posteriorly. The cervicals were shorter, half the torso length. The tail was shorter and more gracile. Extended hemal arches and zygopophyses are present, but extremely gracile. The sternal complex was more circular. The humerus was greatly reduced. The ulna and radius were shorter. Manual digits II and III were subequal. The wing was slightly shorter. The ischium was broader, higher and smaller. The small foot was just longer than half the tibia. Metatarsal I was longer than mt II. Pedal 5.1 extended nearly to the ungual of digit IV.

TM13104
TM 13104 (Winkler 1870, No. 34 in the Wellnhoger 1970 catalog) was considered a juvenile Pterodactylus, but it is unrelated. Distinct from ScaphognathusNo. 110, the skull of No. 34 was shorter with a larger orbit. Following a shallow premaxilla, the naris was still separate from the antorbital fenestra The medial premaxillary teeth were oriented anteriorly. The rostral teeth were the same size and tiny. Extended hemal arches and zygopophyses were absent, but the caudals were more robust. The sternal complex shield was anteroposteriorly shorter with lateral processes enlarged. The scapula was subequal to the coracoid. The metacarpus was greatly elongated and subequal to the ulna. The proximal wing elements were longer such that the joint between m4.2 and m4.3 was beyond the elbow. The ischium was broad and its rims approach both the pubis and ilium. Metatarsal V was shorter. The metatarsals were not appressed.

Gmu-10157
Gmu-10157 (undescribed) was considered a juvenile Pterodactylus, but it is unrelated. Distinct from No. 34, the skull of Gmu-10157 had a longer skull and deeper premaxilla, as in Scaphognathus, No. 110. The antorbital fenestra was elongated anteriorly and the naris was greatlty reduced to the size of the secondary naris. The teeth were larger than in No. 34 and smaller than in No. 110. The postorbital was raised to the top of the orbit. The cervicals were elongated. The humerus was more elongated and robust. Fingers I-III were longer. The prepubis was broader. The ischium was smaller. The tibia was more robust. Pedal digit V was longer.

Relatively Gigantic Yixianopterus is Where Cycnorhamphids and Ornithocheirds Part Company
Yixianopterus jingangshanensis JZMP V-12 (Lü et al. 2006) ~20 cm skull length, Barremian/Aptian Early Cretaceous ~125 mya, was considered an ornithocheirid pterosaur like Haopterus, but it also nests at the base of the Cycnorhamphidae. Overall much larger than and distinct from Gmu-10157, the skull of Yixianopterus was probably longer judging by the pre-antorbital fenestra portion and the mandible. The teeth were more widely spaced. The caudals were shorter. Fingers I-III were smaller, but the wing finger was much more robust. Manual 4.1 approached the elbow when folded and the wingtip was higher than the skull when quadrupedal. The pelvis and tibia were more robust.

Then (Perhaps) Another Size Decrease with BSp 1968 XV 132
Distinct from Yixianopterus, the skull of BSp 1968 XV 132 was longer and lower with more and smaller teeth. The mandible was similarly gracile. The cervicals were longer with tall neural spines. The torso was relatively smaller and shallower. The pectoral girdle was smaller. The humerus was longer and the entire wing was more gracile. Manual 4.1 extended only to the mid ulna. Fingers 1-3 were even smaller. The ilium was more gracile with a greatly reduced posterior process. The tibia was longer and more gracile. The pes was relatively smaller.

And Another Size Decrease with No. 30
B St 1936 I 50 (no. 30 in the Wellnhofer 1970 catalog) ~2.5 cm skull length, Late Jurassic ~150 mya. Standing ~7 cm tall, this is one of the smallest of all known pterosaurs. If it was an adult, eggs were no more than 3 mm in diameter. Much smaller than and distinct from BSp 1968 XV 132, the skull of no. 30 was relatively smaller with a shorter rostrum. The cervicals had short neural spines. The torso was longer. The sternal complex was wider. The coracoid was longer. The humerus was longer and more robust. The wing finger was more gracile. The pubis was directed ventrally. The prepubis had a large perforation. The feet were larger and digit V was especially enlarged.

A Size Increase with Cycnorhamphus
Cycnorhamphus suevicus GPIT specimen (Pterodactylus suevicus Quenstedt 1855, Cycnorhamphus suevicus Seeley 1870, no. 53 in the Wellnhofer 1970 catalog) Kimmeridgian, Late Jurassic ~150mya, ~1.3 meter wingspan, was considered species of Pterodactylus, then a ctenochasmatid. Overall much larger than and distinct from No. 30, the skull of Cycnorhamphus was more robust with a large parietal crest with a narrow frontal contribution. The anterior maxilla was slightly upturned. The teeth were longer in the anterior portion of the jaws. The eighth cervical was reduced. The torso was shorter (more compact) with a larger porportion devoted to the sacrals. The sternal complex was rounder, lacking any of the sharp corners found in No. 30. The scapula was shorter and more laterally oriented. The humerus was shorter, but the elbow still extended posteriorly just to the tip of the ilium. The metacarpals were longer as were fingers I-III. Digit III was an ungual longer than II. The pelvis was more robust. The tibia was longer in concert with the metacarpus such that the wrist and knee remained aligned. Pedal digits II and V were further elongated.

A Slightly Larger Cycnorhamphus
Formerly Gallodactylus, C.  canjuersensis MNHN CNJ 71 (Fabre 1974, 1976; Bennett 1996) is about 40 per cent larger overall, had a shorter wing (not higher than the skull when folded) and a distinct coracoid and pelvis shape. The “prefrontal” of Fabré (1974, 1976) appears to be a lacrimal. The “quadrate” appears to be metacarpal 3 due to its rod-like shape, expanded distal articular surface and proximity to mc IV. The “pterygoid” appears to be the ectopalatine. The “right jugal” appears to be a quadrate due to its angle, position and simple broad shape. The “left corocoid” is a short scapula and the attached “humerus (H.d)” is a coracoid, as Bennett noted. The other “humerus (H.g)” is only half the relative size of the humerus in C. suevicus, so it appears to be another attached scapula.

Another Even Larger Cycnorhampus
A much larger private specimen known only from a skull and jaw with a peculiar vomer expanded into a half disc that fit into a bent mandible can be attributed to Cycnorhamphus, but it is a distinct species.

Feilongus
Feilongus youngi (Wang, Kellner, Zhou and Campos, 2005)~30 cm skull length, Barremian-Aptian, Lower Cretaceous ~125 mya, was considered a ctenochasmatid and an ornithocheirid. Larger overall and distinct from Cycnorhamphus, the skull of Feilongus had a rostrum twice as long. The dorsal margin of the skull was concave from tip to tip. More teeth that were more widely spaced lined the anterior jaws. The anterior rostrum was spoon-shaped.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References:
Bennett SC 2010. The Morphology and Taxonomy of Cycnorhamphus. Acta Geoscientica Sinica 31 Supplement 1, The Flugsaurier Third International Symposium on Pterosaurs.
Lü J, Ji S, Yuan C, Gao Y, Sun Z and Ji Q 2006. New pterodactyloid pterosaur from the Lower Cretaceous Yixian Formation of Western Liaoning. In J. Lü, Y. Kobayashi, D. Huang, Y.-N. Lee (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium. Geological Publishing House, Beijing 195-203.
Wellnhofer P 1975a. Teil I. Die Rhamphorhynchoidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Allgemeine Skelettmorphologie. Paleontographica A 148: 1-33.1975b. Teil II. Systematische Beschreibung. Paleontographica A 148: 132-186. 1975c. Teil III. Paläokolgie und Stammesgeschichte. Palaeontographica 149: 1-30.

The Family Tree of the Pterosauria 15 – Pteranodon

We just looked at the base of the Protopteranodontia and Nyctosaurus. Today we’ll finish up the Pteranodontia with everyone’s favorite, Pteranodon, then later move over to the Cycnorhamphus/Ornithocheirid clade.

Pteranodon skulls

Figure 1. Click to enlarge. A family tree of Nyctosaurus and Pteranodon. Note the gradual size increase followed by, in one lineage, a size decrease.

No one has contributed more to our understanding – and misunderstanding – of Pteranodon (Marsh 1876) more than Dr. S. Chris Bennett. His detailed and unprecedented 1991 PhD thesis on Pteranodon was subsequently split into several published papers (Bennett 1992, 1993, 1994) culminating with a reprinting of his PhD thesis in two parts (2001). Bennett’s hypotheses on pterosaur juveniles, growth, bone fusion and family trees have been the basis for many current studies. Unfortunately, his use of statistics, rather than phylogenetic analysis and his reliance on the outdated archosaur paradigm, rather than the new lizard model, has created problems  in his assessments of growth patterns, gender and speciation in Pteranodon and other taxa.

Two species or several?
Bennett (1991, 1992,  1993, 1994, 2001) reduced Pteranodon to two species: the holotype P. longiceps and the high-crested P. sternbergi. All other variations (Figure 1) Bennett ascribed to gender and immaturity. Phylogenetic analysis tells a different story. I analyzed the specimens above (Figure 1) and found a huge variety that nested in a phylogenetic sequence. Smaller taxa generally were more primitive (but the exceptions (R-V and Z4 in Figure 1) tell another story, see below).  P. occidentalis YPM 1179 (Marsh 1876) is the one closest to the outgroup, the private specimen of Germanodactylus, SMNK PAL 6592. Here a gradual increase in size and crest size, among many other traits is documented followed by a size decrease in a clade descending form a sister to P. ingens.

The Triebold specimen and UALVP 24238, the two most complete Pteranodon known

Figure 2. Click to enlarge. The Triebold specimen and UALVP 24238, the two most complete Pteranodon known. These two are nearly sister taxa and still the morphological variation is striking.

Kellner assigned some Pteranodon specimens to new genera
Kellner (2010) reassigned the Alberta specimen, UALVP 24238, (Z in Figure1) to a new genus and species: Dawndraco kanzai because the upper and lower margins of the rostrum were nearly parallel to one another, rather than tapering, as in all other specimens. Bennett (1991, 1994, 2001) had a assigned it to P. sternbergi. Here the Alberta specimen was derived from USNM 12167 (W in Figure 1) and is at the base of a clade of two other tall but slender crested Pteranodon specimens, AMNH 5099 and YPM 2473 (Z2 and Z3 in figure 1), both of which lack a rostrum for comparison. So a new genus does not appear warranted, only a new species: Pteranodon kanzai. Kellner (2010) also reassigned Pteranodon sternbergi FHSM VP 339 (Harksen 1966) to a genus previously erected by Miller (1972), Geosternbergia sternbergi. Again, considering the wide variation in species within several other widely recognized pterosaur genera (Rhamphorhynchus, Pterodactylus, Campylognathoides, Dorygnathus, etc.), such an assignment appears to be unwarranted until all these other genera are similarly split apart. Actually there is greater morphological disparity in several other Pteranodon specimens, but this was overlooked.

Gradual Increase in Size Followed by Gradual Decrease
We’ve already seen what happens in various other pterosaur clades as size increase is followed by decrease and followed again by increase. We see the same pattern in Pteranodon. Phylogenetically the largest specimens in the P. ingens clade were followed by smaller specimens. Of greater interest, these specimens had a shorter rostrum and an unfused scapulocoracoid, a pattern seen in other pterosaurs lines. Bennett (1991) and others ascribed a short rostrum and lack of fusion to immaturity (following the archosaur model). But that is false. Pterosaurs were lizards with lizard-like growth patterns. In living lepidosaurs, Maisano (2002) reported, “no terminal fusion universally coincides with the achievement of either sexually or skeletally mature size and that some squamates continue to grow long after the fusion of various elements.” Thus pterosaurs, as squamates, could have fused bones early in ontogeny. They could also have never fused certain bones before they died of old age. Under the squamate paradigm, “immature” bone texture could have been retained in phylogenetically smaller adults. This is a key fact that has been previously overlooked or ignored by Bennett and others. And that’s why you only find unfused scapulocoracoids in these smaller derived taxa (R, S, T and Z4 in Figure 1), not in the more primitive taxa (L – N ) of similar size.

Post-crania Pteranodon

Figure 3. Click to enlarge and identify. Various Pteranodon specimens known from post-crania. Note the yellow box includes one of the largest specimens, but it has an unfused extensor tendon process, which may mean it is a very large Nyctosaurus with fingers, following the pattern in primitive Nyctosaurus.

Over 1000 Specimens, Few Even Close to Complete.
Unfortunately, most Pteranodon corpses did not stay intact on their way to the sea floor. That makes it more of a puzzle with smaller pieces to work with. Very few skulls are associated with post-crania. Skull-only and skull-less taxa are the rule. Can they be correlated? The answer is yes, at least somewhat. Fortunately we know more about the P. sternbergia clade because we have two relatively complete specimens from that clade (Figure 2). When we employ skull and skull-less taxa together we get much less phylogenetic resolution because there are no traits certain sisters have in common. However if we run two analyses, one with skulls and one without, then we don’t have that problem. What we get our two very similarly split trees that enable us to match certain post-crania with skulls by the process of elimination and phylogenetic analysis (Figure 4).

Comparing Pteranodon Skull and Skull-less taxa

Figure 4. Click to enlarge. Comparing Pteranodon skull and skull-less taxa. The three main clades (basal, P. ingens and P. sternbergi) are recovered either way.

What We Can Learn from a Juvenile Pteranodon
Several years ago, a juvenile Pteranodon (informally known as “Ptweety”, Figure 3C) was found and (unfortunately) mounted with lots of putty into a standing reconstruction and sold to a retailer. These actions removed this specimen from the possibility of appropriate academic study. Even so, I was able to see photographs of the in situ specimen, examine casts and talk with the preparator. Ptweey was one-quarter as tall as the largest known pterosaur, P. ingens and had adult proportions (long rostrum, small orbit, wing elements proportional, etc.). That means it would have been twice as tall as a standing hatchling. As in all Pteranodon, the extensor tendon process was fused to manual 4.1.

Lack of Fusion Means Immaturity?
Bennett (1991, etc.) reported on a very large proximal wing phalanx (Figure 3o) without a fused extensor tendon process (YPM 2501), but this specimen belongs to a very large Nyctosaurus.

Female Pteranodon?
Bennett (1991, 1992, 2001) reported on a disassociated pelvis that he believed belonged to a female Pteranodon because it had a deeper pelvic opening than all other Pteranodon pelves, including the Triebold specimen, which has a small crest (which meant it should have also been female). The only problem is, the pelvis in question, KUVP 993, is identical to smaller Nyctosaurus pelves (Figure 5). Here is yet another clue that a big Nyctosaurus roamed the airspace over the Niobrara Sea.

Female Pteranodon?

Figure 5. Pteranodon and Nyctosaurus pelves in left lateral view. A. Pteranodon ingens YPM 1175, reconstructed from Eaton (1910). B. Pteranodon sp. UNSM 50036. C. The TRIEBOLD specimen of Pteranodon, NMC 41-358, tracing from in situ specimen. D. Pteranodon sp. UALVP 24238, tracing from in situ specimen. E. Nyctosaurus bonneri, FHSM VP 21 reconstructed. F. Nyctosaurus gracilis, FMNH 25026 in situ G. Nyctosaurus sp. UNSM 93000, reconstructed. H. The same enlarged 1.85x to reflect the hypothetical pelvis size of the largest known Nyctosaurus (Bennett 2000). I. Dubious Pteranodon? KUVP 993 tracing from extricated specimen and slightly reconstructed. While larger than any other known Nyctosaurus pelvis, KUVP 993 has a pelvic aperture deeper than any Pteranodon (Fig. 3a) and morphologically more similar to Nyctosaurus specimens. The obturator foramen rivals and surpasses the acetabulum diameter in Nyctosaurus, not Pteranodon. Thus KUVP 993 does not represent a female Pteranodon pelvis, but a very large Nyctosaurus pelvis. Scale bar = 10 cm. Black circles are approximate egg diameters able to pass through each pelvic opening. Note C and D are associated with skulls (Fig. 2) in the P. sternbergi lineage.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References:
Bennett SC 1991. Morphology of the Late Cretaceous Pterosaur Pteranodon and Systematics of the Pterodactyloidea. [Volumes I & II]. Ph.D. thesis, University of Kansas, University Microfilms International/ProQuest.
Bennett SC 1992. Sexual dimorphism of Pteranodon and other pterosaurs, with comments on cranial crests. Journal of Vertebrate Paleontology 12: 422–434.
Bennett SC 1993. The ontogeny of Pteranodon and other pterosaurs. Paleobiology, 19:92-106.
Bennett SC 1994. Taxonomy and systematics of the Late Cretaceous pterosaur Pteranodon (Pterosauria, Pterodactyloidea). Occassional Papers of the Natural History Museum University of Kansas 169: 1–70.
Bennett SC 2001. The osteology and functional morphology of the Late Cretaceous pterosaur Pteranodon. Part I. General description of osteology. Palaeontographica, Abteilung A, 260: 1–112. Part II. Functional morphology. Palaeontographica, Abteilung A, 260: 113–153.
Eaton GF 1910. Osteology of Pteranodon. Memoirs of the Connectictut Academy of Arts and Sciences 2:1-38.
Harksen JC 1966. Pteranodon sternbergi, a new fossil pterodactyl from the Niobara Cretaceous of Kansas. – Proceedings of the South Dakota Academy of Science 45: 74–77.
Kellner AWA 2010. Comments on the Pteranodontidae (Pterosauria, Pterodactyloidea) with the description of two new species. Anais da Academia Brasileira de Ciências 82(4): 1063-1084.
Maisano JA 2002. Terminal fusions of skeletal elements as indicators of maturity in squamates. Journal of Vertebrate Paleontology 22:268-275.
Marsh OC 1876. Notice of a new sub-order of Pterosauria. American Journal of Science, Series 3, 11:507-509.
Miller HW 1972. The taxonomy of the Pteranodon species from Kansas. Transactions of the Kansas Academy of Science 74: 1–19.

The Family Tree of the Pterosauria 14 – Nyctosaurus

Earlier we looked at the base of the Protopteranodontia, a clade that originated with a private specimen incorrectly referred to Germanodactylus cristatus. The clade also included No. 13, Eopteranodon and Eoazhdarcho and the Pteranodontia (Nyctosaurus + Pteranodon).

Here we look at Muzquizopteryx and the variety within the genus Nyctosaurus.

Nyctosaurus clade

Figure 1. The clade of Nyctosaurus and kin. Click to enlarge.

Muzquizopteryx
At the base of the genus Nyctosaurus is the smallest, newest and most primitive member of the nyctosaur clade, Muzquizopteryx (Frey et al. 2006). Overall larger than and distinct from No. 13, the skull of Muzquizopteryx had a longer rostrum, a shorter antorbital fenestra. The crest was shorter. The orbit was smaller, the lateral temporal fenestra was larger. The cervicals were more robust and shorter with higher neural spines. The cristospine was longer, The scapula was no longer than the coracoid. The deltopectoral crest was expanded distally. The pteroid was right angled. Fingers 1-3 were larger.The ischium was narrower. The prepubis fenestra was expanded beyond the anterior rim creating an anterior and ventral process. The femur and tibia were shorter. The foot was larger with longer toes. Pedal digit 5 was a vestige. It is not know whether Muzquizopteryx had jaw rim teeth or not.

Nyctosaurus bonneri, the Fort Hays specimen
Nyctosaurus bonneri FHSM VP 2148 (Bonner 1964, Miller 1972) Coniacian, Late Cretaceous was Overall larger than and distinct from Muzquizopteryx, the skull of Nyctosaurus bonneri was downturned anterior to the antorbital fenestra. No crest was present. The postorbital process of the jugal was gracile. The mandible was nearly as deep as the skull. No jaw rim teeth were present. The cervicals were shorter and more robust. The sacrum was coosified. The sternal complex was shorter and wider. The scapula and coracoid were more robust. The deltopectoral crest was greatly enlarged. The metacarpus was elongated. Fingers 1-3 were vestiges, probably because they could not touch the ground. Compared to Eopteranodon, the wing was longer. The distal wing phalanges were relatively longer. The pelvis was relatively smaller. The hind limb and foot were relatively shorter. The increase in wing length and decrease in leg length means this Nyctosaurus probably spent more time flying. The short crest sometimes applied to this specimen is an artifact made of putty.

YPM 2501
Size-wise and according to Bennett (1991, 2001) YPM 2501 is a Pteranodon distal metacarpus and proximal portion of the manual 4.1 (the wing finger). The strange thing is, this specimen is larger than virtually all — if not all — known specimens of Pteranodon — AND — the extensor tendon process is not fused. This specimen is a problem for Bennett (1991, 2001) and most other current pterosaur workers because an unfused extensor tendon process, to them, means an immature specimen (following archosaur growth pattern traits). However, following lizard growth patterns and phylogenic patterns this is probably a Nyctosaurus, because Pteranodon fuse the ETP. Crestless nyctosaurs don’t. This specimen also had larger fingers than later, more derived taxa.

Nyctosaurus nanus
The smallest Nyctosaurus (about the size of Muzquizopteryx) is N. nanus, known only for a humerus and pectoral girdle.

Nyctosaurus gracilis, the Field museum (Chicago) specimen
Distinct from the N. bonneri, the skull of N. gracilis (Williston 1902a, b) FMNH 25026 had a slightly deeper rostral tip and a straighter dorsal margin without the posterior downturn, as in Muzquizopteryx. The mandible was probably thinner, but it is crushed dorsoventrally. The cervicals were slightly smaller. The sacrals were relatively larger. The gastralia were the fewest and thickest among all pterosaurs, forming ventral support to counteract the large moment arm the developed from the fulcrum at the dorsal/sacral interface. The sternal comnplex had a larger cristospine and sharper corners. The scapula was smaller than the coracoid. The deltopectoral crest of the humerus was strongly pinched. The pteroid was enlarged. Manual 4.1 was relatively longer. Manual 4.4 was shorter. The pelvis was larger and the pubis contacted the ventrally expanded ischium leaving a large circular obturator foramen between them. The hind limb and foot were larger, as in Muzquizopteryx.

Nyctosaurus sp. the Lincoln Nebraska state museum specimen 
Distinct from Nyctosaurus gracilis, the dorsals of the Nebraska specimen (Brown 1978, 1986) UNSM 93000, were relatively shorter. The scapula and coracoid were more robust. The deltopectoral crest of the humerus most closely resembled that of Muzquizopteryx. Fingers 1-3 were tiny vestiges. Manual 4.1 extended to mid ulna when folded. Manual 4.4 was probably fused to m4.3 or it was missing and m4.3 became curved. The pubis and ischium did not touch, as in more primitive nyctosaurs. It would have been impossible for the forelimb to develop thrust during terrestrial locomotion. It was likely elevated or used like a ski-pole.

Nyctosaurus sp. – two private crested specimens
Nyctosaurus sp. private specimens KJ1 and KJ2 (Bennett 2003) were derived from a sister to the Nebraska specimens of Nyctosaurus sp. and represent the last of their lineage with no known descendants. Distinct from the Nebraska specimen, the skull of KJ1 (below) had an enormous bifurcated frontal crest and a longer mandible than rostrum. The upper temporal fenestra was not visible in lateral view. The mandible was extremely sharp and ideal for skim or stab fishing. A notarium (fused dorsal vertebrae) was present. The coracoid was smaller and fused to the scapula. The humerus and deltopectoral crest were robust. The extensor tendon process was fused to the first wing phalanx. The pteroid was longer than in other nyctosaurs. Manual 4.1 was not much longer than the metacarpus. In KJ1 it was no longer than the metacarpus. The pelvis was deeper than shorter. The tibia was shorter. Overall KJ2 was slightly larger than KJ1. Contra Bennett (2003) not all Nyctosaurus had a crest. A crest does not mean these were male specimens.

Other “Big” Nyctosaurus specimens
As shown above (Figure 1), most Nyctosaurus were roughly the same size, but there is evidence of larger specimens. The largest was YPM 2501 (above). Bennett 1992 considered a pelvis, KUVP 993, in the size range of Pteranodon to be a female pelvis, but morphologically it belongs to a very large Nyctosaurus. Bennett (2000) also reported on a very large Nyctosaurus skeleton in an abstract. “…although incomplete, is the largest known specimen of Nyctosaurus with an estimated wingspan of 4.5 m.” Such a Nyctosaurus is shown in gray in figure 1, scaled up from the UNSM specimen.

In Summary
Unlike Pteranodon, the ancestry of Nyctosaurus included a very small taxon, No. 13, mislabeled Pterodactylus by Wellnhofer (1970). After that point all subsequent taxa, no matter how large (including YPM 2501) did not fuse the extensor tendon process or the scapula to the coracoid, until we come to the derived crested and privately held nyctosaurs, KJ1 and KJ2. They alone had a notarium, fused the scapula to the coracoid and fused the extensor tendon process to the first wing phalanx. Thus nyctosaurs, like all other pterosaurs, followed lepidosaur growth patterns as shown by phylogenetic analysis. Some nyctosaurus (and pterosaurs like ornithocheirids) grew to adults without fusion. Others fused certain bones.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References:
Bennett SC 1991. Morphology of the Late Cretaceous Pterosaur Pteranodon and Systematics of the Pterodactyloidea. [Volumes I & II]. Ph.D. thesis, University of Kansas, University Microfilms International/ProQuest.
Bennett SC 1992.
 
Sexual dimorphism of Pteranodon and other pterosaurs, with comments on cranial crests. Journal of Vertebrate Paleontology 12: 422–434.
Bennett SC 2000. New information on the skeletons of Nyctosaurus. Journal of Vertebrate Paleontology 20 (Supplement to Number 3):29A.
Bennett SC 2001. The osteology and functional morphology of the Late Cretaceous pterosaur Pteranodon. Part I. General description of osteology. Palaeontographica, Abteilung A, 260: 1–112. Part II. Functional morphology. Palaeontographica, Abteilung A, 260: 113–153.
Bennett SC 2003. New crested specimens of the Late Cretaceous pterosaur Nyctosaurus.Paläontologische Zeitschrift 77: 61-75.
Bonner OW 1964. An osteological study of Nyctosaurus and Trinacromerum with a description of a new species of Nyctosaurus. Unpublished Masters Thesis, Fort Hays State University, 63 pages.
Brown GW 1978. Preliminary report on an articulated specimen of Pteranodon Nyctosaurus)gracilis. Proceedings of the Nebraska Academy of Science 88: 39.
Brown GW 1986. Reassessment of Nyctosaurus: new wings for an old pterosaur. Proceedings of the Nebraska Academy of Science 96: 47.
Frey E, Buchy M-C, Stinnesbeck W, González AG, and di Stefano A. 2006. Muzquizopteryx coahuilensis n.g., n. sp., a nyctosaurid pterosaur with soft tissue preservation from the Coniacian (Late Cretaceous) of northeast Mexico (Coahuila). Oryctos 6:19-39.
Miller HW 1972. 
The taxonomy of the Pteranodon species from Kansas. Transactions of the Kansas Academy of Science 74: 1–19.
Williston SW 1902a. On the skeleton of Nyctodactylus, with restoration. American Journal of Anatomy 1: 297–305.
Williston SW 1902b. On the skull of Nyctodactylus, an Upper Cretaceous pterodactyl. Journal of Geology 10: 520–531.

wiki/Nyctosaurus

The Family Tree of the Pterosauria 13 – The Base of the Pteranodontia

We just looked at the various crested descendants of Germanodactylus cristatus, the Dsungaripteridae, the Shenzhoupteridae and the Tapejaridae (part 1 and part 2). Here we look at another, taller specimen of Germanodactylus with a more typical shoulder joint  that was not at the bottom of the torso. This taller specimen is private and undescribed, but assigned the number SMNK-PAL 6592 during its loan to the Stuttgart Museum. It was derived from a sister to Elanodactylus and basal to the most iconic of all pterosaurus, Pteranodon along with Nyctosaurus and Eopteranodon.

Protopteranodontia

Figure 1. The Protopteranodontia. Led by a specimen referred to Germanodactylus cristatus and Elanodactylus, tiny No. 13 is basal to the Pteranodontia, including Eopteranodon, Nyctosaurus (including Muzquizopteryx and Pteranodon.

Elanodactylus
Originally considered close to azhdarchids and ctenochasmatids, the two specimens of Elanodactylus are known principally from complete wings much larger than those of other Germanodactylids. The metacarpus was relatively smaller. The proximal wing phalanx was shorter than the second wing phalanx. Fingers 1-3 were robust.

The SMNK (private) specimen referred to Germanodactylus cristatus
Overall larger and distinct from the BMM specimen, in the  SMNK Germanodactylus the anterior tooth was larger and elevated to the directly anterior orientation creating a sharper snout that was longer than the mandible. The rostral margin was straight and terminated in a small posteriorly-oriented parietal crest. The antorbital fenestra was larger. The rostrum was deeper. The sternal complex was larger with sharper corners. The deltopectoral crest was displaced distally, away from the proximal articular surface. The distal humerus was expanded. The pelvis was longer. The femur was much longer, subequal to the tibia. No three unguals were aligned. Manual 1.1 was longer and m2.1 was shorter. The skull is a close match to that of the most primitive Pteranodon, P. occidentalis.

B St 1878 VI 1 (No. 13)
Overall much smaller than and distinct from SMNK-PAL 6592, the skull of No. 13 was relatively smaller. The orbit was larger and the antorbital fenestra was smaller. The lacrimal was larger. The mandibular symphysis was longer and slightly more deeply keeled. The cervicals were more gracile. The sacrals were shorter. The caudals were smaller. The humerus was smaller. The distal wing elements were shorter. Fingers I-IV were more robust and shorter. The pelvis was shorter with a larger space between the pubis and ischium. The hind limb was shorter and more robust. Metatarsal III was as long as mt II. Pedal unguals II-IV were aligned. Pedal 2.1 was shorter than p2.2. The skull of No. 13 nests at the base of Muzquizopteryx plus  Eopteranodon.

Eopteranodon and Eoazhdarcho
Overall much larger than No. 13, the mandible of Eopteranodon was reported as toothless and crested. The scapula was longer than the coracoid. The humerus was tongue-shaped and more robust. The metatacarpals were longer than the ulna/radius. Fingers 1-3 were more gracile. The proportions of the wing phalanges are unchanged relative to the rest of the forelimb. The pubis included a posterior process. The ischium was not so expanded distally. The anterior process of the posterior ilium was angled dorsally. The prepubis was shallower. The femur was longer. The tibia was relatively longer, in keeping with the metacarpus and manual 4.1. The pes was relatively smaller. It is likely that Eopteranodon and Eoazhdarcho are congeneric. Data with greater resolution should be able to solve this problem.

The great length of the metacarpus in Muzquizopteryx/Nyctosaurus may be inherited from the long metacarpus of Eopteranodon, but Muzquizopteryx/Nyctosaurus had shorter legs and a shorter neck.

Bakonydraco galacz (Osi, Weishampel and Jianu 2005) Santonian ~84 mya, Late Cretaceous, was considered an azhdarchid, but it shares few traits with those flat-jawed pterosaurs. Known form a mandible and perhaps some cervicals found nearby, Bakonydraco is more closely allied with Eopteranodon and Eoazhdarcho, which are unrelated to azhdarchids.

Muzquizopteryx and Nyctosaurus
We’ll discuss this lineage next.

Pteranodon
And the day after that.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References:
Lü J-C and Zhang B-K 2005. New pterodactyloid pterosaur from the Yixian Formation of western Liaoning. Geological Review 51 (4): 458–462.
Lü J-C and Ji Q 2006. Preliminary results of a phylogenetic analysis of the pterosaurs from western Liaoning and surrounding area. Journal of the Paleontological Society of Korea 22 (1): 239–261.
Lü J, Unwin DM, Xu L and Zhang X 2008. A new azhdarchoid pterosaur from the Lower Cretaceous of China and its implications for pterosaur phylogeny and evolution. Naturwissenschaften,
Ösi A, Weishampel DB and Jianu CM 2005. First evidence of azhdarchid pterosaurs from the Late Cretaceous of Hungary. Acta Palaeontologica Polonica 50 (4): 777–787. online pdf
Wellnhofer P 1970. Die Pterodactyloidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Abhandlungen der Bayerischen Akademie der Wissenschaften, N.F., Munich 141: 1-133.
Zittel KA 1882.  Über Flugsaurier aus dem lithographischen Schiefer Bayerns. Palaeontographica 24: 47-81.

wiki/Eopteranodon
wiki/Bakonydraco
wiki/Muzquizopteryx
wiki/Pteranodon

The Family of the Pterosauria 12 – The Tapejaridae (2 of 2)

Today we finish our look at the three clades based on Germanodactylus cristatus (the holotype, n 61 in the Wellnhofer (1970) catalog). We just looked at the Dsungaripteridae, the Shenzhoupteridae and the base of the Tapejaridae. Now we come to the largest and most derived members of the Tapejaridae: Tupuxuara and Thalassodromeus.

The Tapejaridae

Figure 1. The Tapejaridae, including Sinopterus, Huaxiapterus, Tapejara, Tupandactylus, Tupuxuara and Thalassodromeus

Tupuxuara 
Tupuxuara is known from several specimens and one complete cast. Having seen the cast, most of it appears to be real, so that’s the data I’m working with.

The family tree of Germanodactylus.

Figure 2. Click to enlarge. The family tree of Germanodactylus.

Tupuxuara longicristatus, T. leonardii (Kellner & Campos, 1988, 1994) ~110 mya, Late Aptian, Early Cretaceous. Distinct from Tapejara and Huaxiapterus, the skull and mandible were longer with a dorsally expanded and combined rostral and cranial crest. The mandible had a deeper keel. The torso was short and deep. The sacrum was coosified. The sternal complex was large with sharp corners. The humerus was more robust and the deltopectoral crest was smaller. Fingers 1-3 were smaller. The pelvis was smaller and completely coossified. Judging from the cast, the pes was still digitigrade converging on the pedal configuration of basal Pteranodon. Metatarsal 2 was the longest, but digit 4 extended further from the heel.


Martill and Naish (2006) among others nest Tupuxuara with azhdarchids, like Quetzalcoatlus, but there is little to justify this placement other than the convergent enlargement of the antorbitral fenestra higher than the orbit. In the larger analysis azhdarchrids and tapejarids are not related.


Thalassodromeus
Thalassodromeus sethi DGM 1476-R (Kellner and Campos 2002) ~110 mya, Late Aptian, Early Cretaceous, ~1.4 m skull length, was derived from a sister to Tupuxuara longicristatus and represents the last of this lineage. Distinct from Tupuxuara longicristatus, the skull of Thalassodromeus had a greatly expanded combined rostral and cranial crest that expanded further posteriorly. The lower orbit was almost completely ossified. The postorbital process of the jugal was nearly at right angles to the jawline. Two fenestra perforated the crest above the orbit. The posterior jugal was deeper.

The Goshura specimen
The Goshura skeleton has not been described. The illustration in Figure 1 is based on a cast at the Goshura Museum in Japan. I do not know the scale, nor do I know how much of the skeleton is based on a real specimen, nor do I know where the actual specimen is curated. It is distinct enough to be noted and the skull closely matches one I had seen several years ago at the Tucson Gem and Mineral show (Figure 2). The juvenile skull PAL 4303 (Figure 1) is also a close match except the orbit did not lean so much.

Distinct from Thalassodromeus, the skull of the Goshura specimen had a straighter crest margin, a larger orbit and the parietal emerged posteriorly at the level of the orbit. Distinct from Tupuxuara longicristatus, the wings and legs were longer.

Juvenile Tupuxuara

Figure 2. Click to enlarge. Juvenile Tupuxuara. Colors denote various bones. Note the expansion of the nasal dorsally as in laminates the premaxilla to strengthen it.

Juvenile? Tupuxuara
This skull drawing is based on specimen seen at Tucson Gem and Mineral Show several years ago. Not sure where it is now. Compared to the Goshura specimen (above) this skull gives some indication of crest development during growth, if this is not simply a phylogenetic precursor. The skull bones are colored here. Note that the tip of the rostrum is the single remaining tooth.


Countering earlier claims by Kellner and Campus (2002), Humphries et al. (2007) concluded that pterosaurs did not skim feed based on their studies with a jaw fragment they attributed to Thalassodromeus. Unfortunately that jaw fragment was that of a dsungaripterid. There are plenty of pterosaurs with an extremely thin mandible tip, such as Pteranodon and Nyctosaurus. Such jaw tips, whether the rostrum was longer or the mandible was longer, were ideal for spear feeding while on the wing. Read more about this hypothesis here. The jaw tips are unknown in Thalassodromeus, but in sister taxa, such as Tupuxuara, the jaws are also quite narrow at the tip, good for spear feeding.


As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References:
Humphries S, Bonse RHC, Witton M and Martil DM 2007. Did Pterosaurs Feed by Skimming? Physical Modelling and Anatomical Evaluation of an Unusual Feeding Method, PLoS Biol 5(8): e204. doi:10.1371/journal.pbio.0050204 online paper
Kellner AWA and Campos DA 1988. Sobre un novo pterossauro com crista sagital da Bacia do Araripe, Cretaceo Inferior do Nordeste do Brasil. (Pterosauria, Tupuxuara, Cretaceo, Brasil) Anais de Academia Brasileira de Ciências, 60, 459–469.
Kellner, AWA and Campos DA 1994. A new species of Tupuxuara (Pterosauria, Tapejaridae) from the Early Cretaceous of Brazil. An. Acad. Brasil. Ciênc. 66, 467–473.
Kellner AWA and Campos DA 2002. The function of the cranial crest and jaws of a unique pterosaur from the early Cretaceous of Brazil. Science, 297 (5580): 389-392.
Martill DM and Naish D 2006. Cranial crest development in the azhdarchoid pterosaurTupuxuara, with a review of the genus and tapejarid monophyly. Palaeontology 49, 925-941.
Witton MP 2009. A new species of Tupuxuara (Thalassodromidae, Azhdarchoidea) from the Lower Cretaceous Santana Formation of Brazil, with a note on the nomenclature of Thalassodromidae, Cretaceous Research 30′(5): 1293-1300.

wiki/Thalassodromeus
wiki/Tupuxuara

The Family of the Pterosauria 11 – The Tapejaridae (1 of 2)

In our look at the descendants of Germanodactylus cristatus we earlier looked at the Dsungaripteridae and the Shenzhoupteridae. Today we take on the first half of the spectacular Tapejaridae.

The Tapejaridae
The discovery of the strange skull of Tapejara (Kellner 1989) opened to the door to this large-crested clade, often preserved with soft tissue crests that extended the bone shape. While resembling crested Pteranodon in several aspects, all the similarities were by convergence, although the two clades did share a common ancestor in a sister to Germanodactylus rhamphastinus.

The Tapejaridae

Figure 1. The Tapejaridae, including Sinopterus, Huaxiapterus, Tapejara, Tupandactylus, Tupuxuara and Thalassodromeus

Sinopterus
Sinopterus dongi IVPP V13363 (Wang and Zhou 2003) wingspan 1.2 m, 17 cm skull length, was linked to Tapejara upon its discovery. Derived from a sister to Germanodactylus cristatus and Nemicolopterus, the skull of Sinopterus had a convex dorsal profile created by an expanded antorbital fenestra. The lacrimal and nasal were greatly expanded. The jugal was deeper, but the orbit remained large. The mandible was deeper. The palate was relatively twice as wide. The sacrals were nearly one half of the torso, but the torso remained rather elongated. The sternal complex was pentagonal. The radius and ulna were elongated. Manual 3.1 was longer than m2.1. Manual 4.1 was longer than the metacarpus. Manual 4.2 extended past the elbow. Metatarsal 3 was the longest. The proximal pedal phalanges were elongated such that p1.1 was subequal to p2.1 and p3.1.

Huaxiapterus
Huaxiapterus jii GMN-03-11-001 (Lü and Yuan 2005) Aptian, Early Cretaceous, wingspan 9.4 m, 18.5 cm skull length, was considered a distinct taxon when first described, then relegated to a species of Sinopterus. Here Huaxiapterus is indeed a distinct taxon. The skull was shorter with a pronounced “bump” on the rostrum. The antorbital fenestra was taller. The jugal leaned posteriorly. The cranial crest was shorter. The upper temporal fenestra was smaller. The mandible was deeper and shorter. The cervicals were longer and more gracile. The dorsals were longer relative to the sacrals. The short ribs indicate the torso was not deep. The caudals were vestigial. The humerus and metacarpus were longer. Fingers 1-3 were more robust. Manual 3.1 was only slightly longer than m2.1. The pelvis was smaller. The prepubis was shorter. The pubis produces a posterior process. The fibula was a vestige. Metatarsal IV was the longest. Digits II-IV were aligned distally. The proximal phalanges were shorter.

The family tree of Germanodactylus.

Figure 2. Click to enlarge. The family tree of Germanodactylus.

Tapejara
Tapejara wellnhoferi (Kellner 1989) ~108 mya, Early Cretaceous was immediately recognized as something quite different when first discovered. Distinct from Huaxiapterus, the skull of Tapejara was shorter with a taller rostral crest. The mandible was deeper. The jugal did not lean as much. The cervicals were shorter. The sacrals were longer (judging by the pelvis). The humerus was more narrowly waisted. The rest of the wing was more gracile, including the fingers. The posterior process of the pubis was further expanded creating an obturator foramen between it and the broad ischium. The prepubis was angled anteriorly. The hind limbs were shorter. The fibula was barely present.

Tupandactylus
Tupandactylus imperator (Campos and Kellner 1997) ~110 mya, Late Aptian, Early Cretaceous is one of the most spectabular pterosaurs ever discovered. Distinct from Tapejara, the skull of Tupandactylus was longer with an even taller rostral crest and a longer cranial crest. Between them a soft tissue crest spanned these masts. The nasal, maxilla and even a process of the jugal expanded dorsally to laminate with and support the premaxillary crest. The premaxilla topped the frontal and parietal extending far posterior to the back of the skull to create an elongate bony crest that served as the base for a very large soft-tissue crest much larger in lateral area than the entire skull.

Next time we’ll finish up the Tapejaridae with its largest and most derived members, Tupuxuara and Thalassodromeus.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References:
Kellner AWA 1989. A new edentate pterosaur of the Lower Cretaceous from the Araripe Basin, northeast Brazil. Anais da Academia Brasileira de Ciências 61, 439-446.
Wang X and Zhou Z 2003. A new pterosaur (Pterodactyloidea, Tapejaridae) from the Early Cretaceous Jiufotang Formation of western Liaoning, China and its implications for biostratigraphy. Chinese Science Bulletin 48:16-23.
Li J, Lü J and Zhang B 2003. A new Lower Cretaceous sinopterid pterosaur from the Western Liaoning, China. Acta Palaeontologica Sinica 42(3):442-447.
Lu J, Jin X, Unwin DM, Zhao L, Azuma Y and Ji Q 2006. A new species of Huaxiapterus (Pterosauria: Pterodactyloidea) from the Lower Cretaceous of Western Liaoning, Cina with comments on the systematics of Tapejarid pterosaurs: Acta Geologica Sinica, v. 80, n. 3, p. 315-326.7. (H. corrollatus)
Lü J, Gao Y, Xing L, Li Z and Ji Q 2007. A new species of Huaxiapterus (Pterosauria: Tapejaridae) from the Early Cretaceous of Western Liaoning, China: Acta Geologica Sinica, vol.81, no.5, p.683-687. (H. benxiensis)
Lü J and Yuan C 2005. New Tapejarid Pterosaur from Western Liaoning, China. Acta Geologica Sinica 79 (4): 453-45 (H. jii)

wiki/Sinopterus
wiki/Huaxiapterus
wiki/Tapejara
wiki/Tupandactylus

The Family Tree of the Pterosauria 10 – The Shenzhoupteridae

Updated April 5, 2016 with new images of Nemicolopterus

Earlier we looked at the rise of Germanodactylus,  the clade of Germanodactylus and the Dsungaripteridae. Today we look at the Shenzhoupteridae. The Tapejaridae will follow.

The Shenzhoupteridae
Shenzhoupterus was originally considered an “azhdarchoid” sister to ChaoyangopterusJidapterusEoazhdarcho and Eopteranodon. Unfortunately the first two and the second two actually belong to two unrelated clades far removed from each other and distinct from Shenzhoupterus according to the present cladistic analysis. However, to the credit of its authors, tiny Nemicolopterus was originally recognized as a sister to Shenzhoupterus. At present these are the only two taxa known for this clade.

Figure 1. Germanodactylus cristatus and members of the Shenzhoupteridae, Nemicolopterus and Shenzhoupterus.

Figure 1. Germanodactylus cristatus and members of the Shenzhoupteridae, Nemicolopterus and Shenzhoupterus.

Nemicolopterus crypticus IVPP V-14377 (Wang et al. 2008) ~120 mya, Aptian, Early Cretaceous, ~25 cm wingspan, was a very tiny pterosaur, but to the credit of its describers they considered it a sub-adult rather than a hatchling. Derived from a sister to the much larger Germanodactylus critatusNemicolopterus was a sister to the much larger Shenzhoupterus. The skull of Nemicolopterus was more gracile, with a large orbit and a larger cranial crest without any rostral crest. A minor dentary keel was present. No teeth were present. The cervicals were robust and not elongated. The dorsals were compact. The ribs and gastralia were horizontally oriented creating a wider than typical torso. This is reflected in the wide shapes of the scapulocoracoid and the sternal complex. The sternal complex was over three times wider than long. The laterally directed coracoid produced a “bottom-decker” wing. The forelimb was more robust, but the wing and fingers 1-3 were not. The hind limb was shorter. All four metatarsals were subequal. Pedal digit I was elongated such that all four unguals were aligned. Pedal digit 4 extended the furthest from the heel. Perhaps the small size of Nemicolopterus is yet another example of size reduction during a morphological change from one large taxon (Germanodactylus cristatus) to another even larger taxon (Shenzhoupterus). It would be good to find more transitional taxa in the future.

Figure 2. Nemicolopterus has been described as the smallest pterosaur, but No. 6 in the Wellnhofer (1970) catalog was only half as tall.

Figure 2. Nemicolopterus has been described as the smallest pterosaur, but No. 6 in the Wellnhofer (1970) catalog was only half as tall.

Shenzhoupterus chaoyangensis IHGM 41HIII-305A (Lü et al. 2008) ~120 mya, Aptian, Early Cretaceous, ~4.6 m wingspan. Shenzhoupterus was the largest representative of this lineage and lived at the same time as Nemicolopterus. The skull of Shenzhoupterus had a taller antorbital fenestra, a taller subdivided orbit and a thinner, longer posterior crest. The scleral ring occupied the top portion of the subdivided orbit, so was relatively much smaller. The mandible was deeper. The cervicals were elongated and quite gracile. The torso was deep, short and compact, almost spherical. The sacrals equaled the dorsals in length. The caudals were vestigial. The sternal complex was square. The humerus extended to the pubis. The wing was gracile. The pelvis was larger and the prepubis was much deeper. The hind limb was longer and more robust. Pedal digit I was short, as in Noripterus, and the ungual did not align with II-IV.

The original reconstruction (Lü et al. 2008) of the skull simply traced an outline of the chaotic bones en masse (including the sternal complex, which is under the orbit!!!). They also overlooked the long posterior crest. Click here to see a DGS (digital graphic segregation) of the posterior skull elements. The subdivision of the orbit is a trait also seen in dsungaripteridae by convergence. The short round torso is also seen in Tupuxuara by convergence.

 

References:
Lü J, Unwin DM, Xu L and Zhang X 2008. 
A new azhdarchoid pterosaur from the Lower Cretaceous of China and its implications for pterosaur phylogeny and evolution. Naturwissenschaften 95 (9): online (preprint). doi:10.1007/s00114-008-0397-5. PMID 18509616.
Wang X, Kellner AWA, Zhou Z and Campos DA 2008
. Discovery of a rare arboreal forest-dwelling flying reptile (Pterosauria, Pterodactyloidea) from China. Proceedings of the National Academy of Sciences, 106(6): 1983–1987. doi:10.1073/pnas.0707728105

wiki/Nemicolopterus
wiki/Shenzhoupterus


The Family Tree of the Pterosauria 9 – The Dsungaripteridae

Earlier we looked at the rise of Germanodactylus and the clade of Germanodactylus. Today we take a look at the clade of Germanodactylus cristatus (the holotype) including the Dsungaripteridae. The Shenzhoupteridae and the Tapejaridae will follow.

The Dsungaripteridae

Germanodactylus and the Dsungaripteridae

Figure 1. Germanodactylus and the Dsungaripteridae

The relationship between Germanodactylus cristatus and Dsungaripterus was recognized immediately (Young 1964). Traditionally considered toothless and overlooked by all prior workers, the tips of both jaws are actually sharp teeth, a trait inherited from Germanodactylus. The posterior premaxillary teeth are absent. Unfortunately, there aren’t many dsungaripterids known. Several are from partial skulls.

Lonchognathosaurus  (Maisch, Matzke and Sun 2004) is the smallest of the dsungaripterids, known from only a portion of the rostrum.

“Phobetor”
Phobetor” (Yang 1973) was combined with Noripterus by Lü et al. (2009) and is known from a complete skull. Distinct from Germanodactylus cristatus (No. 61), the skull had a smaller and subdivided orbit and a raised cranial crest. The lacrimal produced a posterior process to meet the postorbital, which produced an anterior process to divide the orbit into upper and lower areas. The jawline was straighter. The quadrate angle was raised. The quadratojugal was larger. Teeth erupted only in the middle of the jaws. The mandible was straigther and more gracile.

Noripterus
Noripterus (Yang 1973) is known from postcranial material only. The humerus had a smaller deltopectoral crest that was not medially angled. The metacarpus was longer than the ulna. Fingers I-III were reduced and so were the unguals. Manual 4.2 extended beyond the elbow when the wing was folded. The hind limb was longer and more gracile. The foot was smaller with unguals aligned transversely. The metatarsus was relatively longer and the toes were shorter.

Dsungaripterus
Dsungaripterus (Young 1964) ~4 m wingspan, Early Cretaceous was derived from a sister to Noripterus. Together these dsungaripterids represent the last of their lineage. Distinct from Noripterus, the skull of Dsungaripterus was more robust with upturned jaw tips. Bone grew over the rear teeth during maturation. The suborbital region was further ossified. The mandible was more robust. The sternal complex was rectangular. Posteriorly two sternal ribs (or gastralia) were massive. The gastralia were few and robust. The wing was more gracile. The femur was more robust. The fibula was fused to the tibia.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References:
Bakhurina NN 1982. A pterodactyl from the lower Cretaceous of Mongolia. Paleontological Journal 1982(4): 104-109.
Lü J, Azuma Y, Dong Z, Barsbold R, Kobayashi Y and Lee Y-N 2009. New material of dsungaripterid pterosaurs (Pterosauria: Pterodactyloidea) from western Mongolia and its palaeoecological implications. Geological Magazine, 146(5): 690-700.
Maisch MW, Matzke AT and Sun G 2004. A new dsungaripteroid pterosaur from the Lower Cretaceous of the southern Junggar Basin, north-west China. Cretaceous Research 25: 625–634. doi:10.1016/j.cretres.2004.06.002.
Yang Z 1973. Reports of Paleontological Expedition to Sinkiang (II): Pterosaurian Fauna from Wuerho, Sinkiang (in Chinese). Memoirs of the Institute of Vertebrate Paleontology and Paleoanthropology Academia Sinica 11: 18–35.
Young CC 1964. On a new pterosaurian from Sinkiang, China. Vertebrata PalAsiatica 8: 221-256.

wiki/Dsungaripterus
wiki/Noripterus

The Family Tree of the Pterosauria 8 – The Germanodactylus Clade

We just looked at the ramp up to Germanodactylus rhamphastinus. For a very long time we knew of only two Germanodactylus specimens, G. cristatus (the holotype) and G. rhamphastinus. Now we know of many more (Figure 1) not counting the many descendants. Some taxa within this clade have been assigned to other genera (Eosipterus, Elanodactylus). Others are known only by museum numbers (SMNK PAL 3830, MOZ 36325P). Still others are private specimens loaned to museums (SMNK PAL 6592, the BMM specimen). All this will require nomenclature revision at some time in the future.

Germanodactylus rhamphastinus
Germanodactylus rhamphastinus (Wagner 1851 B St AS I 745, No. 64 of Wellnhofer 1970) was the first of the raven-sized germanodactylids (Figure 1). No. 64 was derived from No. 23 and phylogenetically preceded Eosipterus and JME Moe 12. Distinct from No. 23, the skull of No. 64 was deeper anteriorly and crested posteriorly. The orbit was smaller with a V-shaped ventral margin. The teeth were larger and narrower. The jugal was narrower and deeper. The cervicals were longer and decreased in size cranially. The torso was reduced. The caudals were longer as a set, but most individual caudals remained short. The deltopectoral crest did not lean medially. The humerus was straight. The metacarpus was relatively longer. Fingers I-III were more robust and the unguals were larger. Manual 4.2 extended just to the elbow. The ischium was bifurcated. The prepubis was L-shaped. Pedal digit I was shorter. The unguals were smaller.

Following G. rhamphastinus the germanodactylids spread worldwide. Here they are presented in roughly phylogenetic order.

Germanodactylus and kin

Figure 1. Click to enlarge. Germanodactylus and kin.

Eosipterus
Eosipterus yangi (Ji and Ji 1997) GMV 2117 (not shown in Figure 1) was a headless specimen originally allied with Pterodactylus and Ctenochasma. Distinct from G. rhamphastinus, the humerus of Eosipeterus was shorter and slightly expanded distally. The deltopectoral crest was much larger. The metacarpus was shorter. Fingers 1-3 were smaller. Manual 4.2 extended beyond the elbow when the wing was folded. The ischium was expanded. Pedal unguals 2-4 were aligned transversely. The pedal digits were smaller.

Germanodactylus sp. JME/BSP specimen
The JME specimen of Germanodactylus (Rodriques, Kellner and Rauhut 2010) JME Moe12 (plate) BSP 1977 XIX 1 (counterplate). Distinct from G. rhamphastinus, the skull of JME Moe12 was much sharper with a relatively larger antorbital fenestra and orbit. No ossified crest jutted out from the cranium. The maxilla was slightly concave ventrally. The dentary was slightly convex dorsally to match it. The cervicals were more gracile. The torso was relatively longer. The caudals were reduced. The sternal complex, scapula and coracoid were all reduced. The forelimb was more gracile with smaller fingers. The metacarpus was shorter. Manual 4.1 was shorter than m4.2. The pubis and ischium were not sutured ventrally. The prepubis was shorter. The posterior process of the ilium was no longer than the posteriorly expanded ischium. The hindlimb was longer. The metatarsals and unguals were aligned transversely.

The family tree of Germanodactylus.

Figure 2. Click to enlarge. The family tree of Germanodactylus.

The BMM Germanodactylus
This privately held Late Jurassic pterosaur was on display at the Bürgermeister-Müller-Museum. In his blog Dr. David Hone mislabeled it a Pterodactylus and likewise an image of this specimen appears on the Wikipedia Pterodactylus page. Cladistic analysis (Figure 2) nests the BMM specimen in the middle of other Germanodactylus specimens. Overall it was nearly identical to MOZ 3625P (see below), but more robust. The foot of the BMM specimen is similar to that of  PAL 3830 with a large pedal 1.2 (the ungual) larger than p1.1. This pterosaur and MOZ 3625P (below) nest at the base of a split in the tree between the holotype Germanodactylus cristatus (and its crested tapejarid descendants) and the referred specimen SMNK 6592  (and its crested pteranodontid descendants).

MOZ 3625P
MOZ 3625P was originally considered an indeterminate pterodactyloid. Here it nests within the genus Germanodactylus. The MOZ 3625P skull is not known. Distinct from JME Moe12, the cervicals of MOZ 3625P were longer and more gracile. The humerus was more robust. The pubis and ischium were completely fused.

Germanodactylus cristatus
With the holotype for the genus, Germanodactylus cristatus B St 1892 IV 1 (Pterodactylus kochi Plieninger 1901, Germanodactylus cristatus Wiman 1925, No. 61 of Wellnhofer 1970) we move into another clade that continued the extremely sharp jawed morphology. The shoulder joint was shifted to the ventral torso, the so-callled “bottom-decker” wing placement. This clade included “Phobetor” in the Dsungaripteridae, Nemicolopterus in the Shenzhoupteridae and Tapejara in the Tapejaridae, to name just a few. No. 61 was also a sister to the long-legged super-clawed pterosaur, SMNK PAL 3830. Distinct from JME Moe 12, the skull of No. 61 was smaller overall and had an ossified rostral crest supporting a larger soft tissue crest. It had a cranial crest oriented posteriorly and posterior processes of the squamosal that formed “ears”. The premaxilla extended along the entire dorsal margin of the skull, including the cranial crest. The vomers were visible in lateral view. The premaxillary teeth were vestigial. The cervicals were longer. The caudals were more robust. The humerus was more robust with a longer deltopectoral crest. The metacarpus was longer. Fingers 1-3 were larger.

SMNK PAL 3830 – The Crato “Azhdarchid”
SMNK PAL 3830 (the Crato “azhdarchid” Frey & Tischlinger 2000) was originally considered an azhdarchid, like Quetzalcoatlus, probably due to its great size. Here it nests as a sister to Germanodactylus cristatus. Distinct from and twice the size of No. 61, fingers 1-3 of PAL 3830 were relatively larger. Manual digit 3 was longer than half the metacarpus and as long as the entire foot. The metacarpus was much more robust than manual 4.1. The foot, while appearing quite lethal, was actually much smaller relatively, reduced to about a third of the tibia. A small patella was present. The penultimate pedal phalanges were the longest in each series suggesting an arboreal habitat when not flying. It’s hard to imagine such claws ever touching the ground.

Elanodactylus
At the base of the other branch of germanodactylids is another oversized germanodactylid, Elanodactylus. Elanodactylus is known chiefly from wing material. Atypical for pterosaurs, manual 4.2 was longer than m4.1. The metacarpals were shorter than in other germanodactylids.  The neck vertebrae were considered similar to those of azhdarchids, but then germanodactylid neck vertebrae have not been well described because often they were often preserved exposed ventrally. Andres and Ji (2008) nested Elanodactylus with ctenochasmatids, but shifting it there adds 9 to 12 steps to the tree.

Germanodactylus sp. SMNK 6592
A private Germanodactylus, SMNK 6592, is basal to Eopteranodon, Pteranodon and Nyctosaurus (including Muzquizopteryx). Overall larger and distinct from the BMM specimen (above), the anterior tooth was larger and elevated to the directly anterior orientation creating a sharper snout that was longer than the mandible, as in Pteranodon. The rostral margin was straight and terminated in a small posteriorly-oriented parietal crest. The antorbital fenestra was larger. The rostrum was deeper. The sternal complex was larger with sharper corners. The deltopectoral crest was displaced distally, away from the proximal articular surface. The distal humerus was expanded. The hindlimbs were longer and more gracile.

Descendant taxa will be covered in future blogs.

A Summary
The genus Germanodactylus began with tiny pterosaurs provided with longer and sharper jaws. At three phylogenetic nodes the jaws became extremely sharp following rotation of the anterior tooth to an anterior orientation on both the upper and lower jaws. The size of this genus varied minimally, but Elanodactylus and the SMNK PAL 3830 specimen were larger than normal exceptions (not counting the very large descendants). Several Germanodactylus specimens had short hard crests that probably supported extensions of soft tissue. The manual fingers and claws of some germanodactylids were quite large and trenchant.

 

References:
Andres B and Ji Q 2008. A new pterosaur from the Liaoning Province of China, the phylogeny of the Pterodactyloidea, and convergence in their cervical vertebrae. Palaeontology51: 453–469.
Ji S-A and Ji Q 1997.
Discovery of a new pterosaur in Western Liaoning, China. Acta Geologica Sinica 71(1): 1-6 [in Chinese].
Rodrigues T, Kellner AWA and Rauhut OWM 2010. A New Specimen of the Archaeopterodactyloid Germanodactylus R[h]amphastinus. Acta Geoscientica Sinica 31(Supp. 1): 57-58.
Zhou C 2009. New material of Elanodactylus prolatus Andres & Ji, 2008 (Pterosauria: Pterodactyloidea) from the Early Cretaceous Yixian Formation of western Liaoning, China.Neues Jahr. Geo. Paläo. Abh. (DOI: 10.1127/0077-7749/2009/0022.)

The Family Tree of the Pterosauria 7 – The Rise of Germanodactylus

We just looked at the smallest of all pterosaurs, B St 1967 I 276, tiny No. 6 from the Wellnhofer (1970) catalog. Descendants grew larger quickly with a larger, sharper rostrum and mandible tipped by a single tooth. Thus began the rise of Germanodactylus and all of its many, varied and crested progeny.

basal germanodactylids

Figure 1. Basal Germanodactylia. Three taxa preceding Germanodactylus rhamphastinus: No. 6, No. 12 and No. 23 all to scale. This rapid size increase succeeded a size shrinkage culminating with No. 6, the smallest of all pterosaurs.

No. 12
Formerly considered a species of Pterodactylus, No. 12 needs a new name because here it nested between two predecessors to Germanodactylus. Twice as tall as No. 6, No. 12 had a much longer and sharper rostrum, the hallmark of the new clade. Like all germanodactylia, a procumbent tooth further sharpened the jaw tips and palatal extensions of the maxilla reinforced them. The antorbital fenestra was only half the rostral length. The teeth were larger. The lacrimal was enlarged. The quadrate angle was elevated. The postorbital was raised. The cervicals were elongated. The caudals were robust. The sternum had sharp posterior corners. The scapula was curved. The ventral coracoid was expanded. The humerus was relatively shorter. The ulna was twice as long as the humerus. The ischium was perforated. The metatarsus was appressed. Pedal 4.4 was shorter.

No. 23
Formerly considered the holotype of the species. Pterodactylus kochi (Wagner 1837 Ornithocephalus? kochi von Meyer 1859), B St ASXIX 3 (plate) SMF No. R 404 (counterplate), No. 23 of Wellnhofer 1970) also needs a new name. It was 2.5 times taller than No. 12. Distinct from No. 12, the skull of No. 23 was sharper, the jugal was deeper, the teeth were larger and the mandible was deeper. The torso was deeper. The dorsal ribs were more robust. The sacrals were relatively larger. Manual 4.3 approaches the elbow. The wing, when folded, barely reaches the top of the cervicals. The pelvis was relatively larger.

Germanodactylus and kin

Figure 2. Click to enlarge. Germanodactylus and kin.

Germanodactylus rhamphastinus
Germanodactylus rhamphastinus (Wagner 1851 B St AS I 745, No. 64 of Wellnhofer 1970) was the first of the raven-sized germanodactylids. No. 64 was derived from No. 23 and phylogenetically preceded Eosipterus and JME Moe 12. Distinct from No. 23, the skull of No. 64 was deeper anteriorly and crested posteriorly. The orbit was smaller with a V-shaped ventral margin. The teeth were larger and narrower. The jugal was narrower and deeper. The cervicals were longer and decreased in size cranially. The torso was reduced. The caudals were longer as a set, but most individual caudals remained short. The deltopectoral crest did not lean medially. The humerus was straight. The metacarpus was relatively longer. Fingers I-III were more robust and the unguals were larger. Manual 4.2 extended just to the elbow. The ischium was bifurcated. The prepubis was L-shaped. Pedal digit I was shorter. The unguals were smaller.

Same genus? Or not the same genus?
Germanodactylus cristatus B St 1892 IV 1 (Pterodactylus kochi Plieninger 1901, Germanodactylus cristatus Wiman 1925, No. 61 of Wellnhofer 1970) was the type specimen for this genus. G. rhamphastinus was referred to the genus. There are only two specimens that nest between the holotype and the first referred specimen, so the morphological disparity, while great, is no more than is found in various specimens attributed to Campylognathoides, Rhamphorhynchus, Pterodactylus and Pteranodon. The trouble comes later with an undescribed specimen referred to Germanodactylus cristatus (SMNK-PAL 6592). At least two unnamed transitional taxa, plus the much larger Elanodactylusseparate it from the holotype.

Next time we’ll examine the wide variety within the genus Germanodactylus.

As always, I encourage readers to see specimens, make observations and come to your own conclusions. Test. Test. And test again.

Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.

References:
von Huene F 1951. Zwei ausgezeichnet erhaltene Exemplare von Pterodactylus im Natur-Museum Senckenberg. Senckenbergiana 32: 1–7.
von Meyer CEH 1859.
 Zur Fauna der Vorwelt. Vierte Abt.: Reptilien aus dem lithographischen Schiefer des Jura in Deutschland und Frankreich.1. Lieferung: 1–84 & pls, 1859 and 2. Lieferung: 85–114 & pls, 1860. Frankfurt am Main: H. Keller. [pp. 7–90, 141–144 & pls 1–10.]
Wagner JA 1851. Beschreibung einer neuen Art von Ornithocephalus nebst kritischer Vergleichung der in derk. Paläontologischen Sammlung zu München aufgestellten Arten aus dieser Gattung. Akademie der Wissenschaften Mathematischen-physikalischen Klasse6: 127–192 & pls 5–6.
Wellnhofer P 1970. Die Pterodactyloidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Abhandlungen der Bayerischen Akademie der Wissenschaften, N.F., Munich 141: 1-133.

wiki/Germanodactylus