New Langobardisaurus Confirms Earlier Findings

There’s a new Langobardisaurus (Figs. 1-3) with hollow limb bones courtesy of Saller, Renesto & Dalla Vecchia (2013). Langobardisaurus, with all of its oddities and wonders deservers a bit more PR. So, here ’tis.

The new Langobardisaurus. A little hard to see, but the neck curves up, left, down and behind the body, with the head emerging on the right.

Figure 1. The new Langobardisaurus. P10121. A little hard to see, but the neck curves up, left, down and behind the body, with the head emerging on the right. The hollow bones are crushed revealing their interiors. No soft tissue is preserved along with the fossil leaves shown here.

Here’s the abstract:
“A new specimen of the small protorosaurian reptile Langobardisaurus pandolfii is described. It was collected from the Seefeld Formation, of Late Triassic (Norian) age, in the Innsbruck area (Austria) and represents the first occurrence of Langobardisaurus outside Italy. Although preserved mostly as an impression, the find is significant

because it extends the palaeogeographic range of the genus and it is the second specimen known to date with the skull fully exposed. The preserved portions of the limb elements show that the bones are hollow, with a layer of compacta and without any trace of spongiosa. Reappraisal of all the specimens assigned to the genus Langobardisaurus reveals no significant differences between L. pandolfii and L. tonelloi, allowing to consider the latter as a junior synonym of the former.”

Not a protorosaur. Not an archosauromorph.
Saller, Renesto and Dalla Vecchia (2013) labeled Langobardisaurus a “small archosauromorph” basing this on conventional thinking linking Langobardisaurus to protorosaurs. We talked about this mistake earlier. The large reptile tree nests Langobardisaurus and its sisters with tritosaur lizards, descended from a sister to Huehuecuetzpalli and Lacertulus. Sister taxa in the large reptile tree include CosesaurusTanystropheusTanytrachelos and Macrocnemus. This clade includes several other long-necked bipeds with sprawling hind limbs (Renesto, Dalla Vecchia and Peters 2002). So Langobardisaurus was an occasional biped, lizard-style.

Saller, Renesto and Dalla Vecchia (2013) report, “All specimens of Langobardisaurus were found in a dark limestone and dolostone that formed in relatively small and deep marine basins surrounded by shallow-water carbonate platforms.” Langobardisaurs appear to be terrestrial reptiles, so their bodies appear to have been swept into these basins from river floods along with the plant debris seen in the fossil.

Figure 2. The skull of the new Langobardisaurus in situ, above, and reconstructed below, using the DGS technique. If there was no antorbital fenestra the rostrum was at least very weak. The left maxilla  itself was broken into several pieces. The skull looks like the other Langobardisaurus skulls, so is likely conspecific.

Figure 2. The skull of the new Langobardisaurus in situ, above, and reconstructed below, using the DGS technique. If there was no antorbital fenestra the rostrum was at least very weak and this taxon immediately preceded a taxon known to have an antorbital fenestra, Cosesaurus. The left maxilla itself was broken into several pieces. The skull looks like the other Langobardisaurus skulls, so is likely conspecific. The dentary is tipped with a tooth-like structure. Note the very tall coronoid process.

Antorbital fenestra
Langobardisaurus (Fig. 2) appears to have had an antorbital fenestra as it now appears in two specimens (Fig. 4) and in Pteromimus (Atanassov 2001), another langobardisaur with an antorbital fenestra.

Skull bones
The premaxilla is reported as edentulous with toothlike-projections erupting from it. Certainly this morphology was distinct and provided a mechanism for prey (insect) acquisition. Perhaps these were teeth fused to the jaws in the manner of sphenodontid teeth.

Most maxillary teeth had two or three cusps, but the posterior-most maxillary and dentary teeth were much longer than the others and bore many tiny cusps. These would have acted like linear molars.

The coronoid process was tall and robust, unlike other tritosaur lizards. No stomach contents tell us what Langobardisaurus ate. But the teeth and coronoid process tell us it was probably crunchy, requiring a certain amount of oral processing.

The pectoral girdle
Earlier we talked about the coracoid and strap-like scapula of Langobardisaurus, relabeled from earlier interpretations. Here (Fig. 3) those identifications are confirmed with similar morphologies and placements.

Figure 3. The pectoral girdle of the new Langobardisaurus highlighted in colors. These elements correspond to those of an earlier Langobardisaurus with an angled coronoid and a strap-like scapula.

Figure 3. The pectoral girdle of the new Langobardisaurus highlighted in colors. These elements correspond to those of an earlier Langobardisaurus with an angled coronoid and a strap-like scapula.

Hollow limbs
The hollow limb bones of Langobardisaurus are shared with members of the Fenestrasauria, including pterosaurs. So are the elongated nares, the large orbits, the elongated pedal 5.1 and the advancement of the sternum toward the clavicles.

Langobardisaurus tonelloi

Figure 4. Langobardisaurus tonelloi. The incomplete tail of this specimen was proabably longer based on other specimens. The the cosesaurid-type pectoral girdle. 

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.

Reference
Atanassov M 2001. Two new archosauromorphs from the Late Triassic of Texas. – Journal of Vertebrate Paleontology Abstracts 21(3): 30A.
Atanassov M 2002. Two new archosauromorphs from the Late Triassic of Texas. Dissertation.online abstract
Muscio G 1997. Preliminary note on a specimen of Prolacertiformes (Reptilia) from the Norian (Late Triassic) of Preone (Udine, north-eastern Italy). Gortania – Atti del Museo Friulano di Storia Naturale 18:33-40
Renesto S 1994. A new prolacertiform reptile from the Late Triassic of Northern Italy. Rivista di Paleontologia e Stratigrafia 100(2): 285-306.
Renesto S and Dalla Vecchia FM 2000. The unusual dentition and feeding habits of the Prolacertiform reptile Langobardisaurus (Late Triassic, Northern Italy). Journal of Vertebrate Paleontology 20: 3. 622-627.
Renesto S and Dalla Vecchia FM 2007. A revision of Langobardisaurus rossii Bizzarini and Muscio, 1995 from the Late Triassic of Friuli (Italy)*. Rivista di Paleontologia e Stratigrafia 113(2): 191-201. online pdf
Renesto S, Dalla Vecchia FM and Peters D 2002. Morphological evidence for bipedalism in the Late Triassic Prolacertiform reptile Langobardisaurus. Senckembergiana Lethaea 82(1): 95-106.
Saller F, Renesto S and Dalla Vecchia FM 2013. First record of Langobardisaurus (Diapsida, Protorosauria) from the Norian (Late Triassic) of Austria, and a revision of the genus. Neues Jahrbuch für Geologie und Paläontologie – Abhandlungen 268(1): 83-95
DOI: http://dx.doi.org/10.1127/0077-7749/2013/0319
Wild R 1980. Tanystropheus (Reptilia: Squamata) and its importance for stratigraphy. Mémoires de la Société Géologique de France, N.S. 139:201–206.

uninisubria/Langobardisaurus
wiki/Langobardisaurus

What Did Langobardisaurus Eat?

Strange body. Strange skull. Strange teeth.

Earlier we looked at the pectoral girdle of this Triassic oddity. The genus Langobardisaurus (Fig. 1) is known from several specimens assigned to two species, L. pandolfii and L. tonelloi. Both have a large skull, large orbit, retracted nares, elongated cervicals, no proximal carpals, a long torso, a great number of gastralia, appressed ulna/radius, appressed tibia/fibula/ and a lizard-like foot with a reduced metatarsal 5 and an elongated p5.1.

Two skulls of Langobardisaurus together with to scale images of them along with sisters Amotosaurus and Pteromimus.

Figure 1. Two skulls of Langobardisaurus together with to-scale images of them along with sisters Amotosaurus and Pteromimus. Note Pteromimus has the most plesiomorphic teeth.

Earlier we also looked at the giant, though still related Tanystropheus, represented by a likely deep water biped with elongated conical teeth feeding on passing cephalopods among elongated crinoids. There are also much smaller specimens with both conical and tricuspid teeth, closer to the dental arrangement in Langobardisaurus, grabbing and crunching, like mammals. Langobardisaurus takes that one step further with an elongated posterior dentary tooth (the result of three fused teeth?). It has a straight processing surface and opposes at least three maxillary teeth.

The orbit was very large, suggesting acute vision (perhaps for night time predation?) The rostrum was narrow, short and pointed, so probably not a fish-eather. There was a possible antorbital fenestra or two, as in its sister Cosesaurus (a small insectivore) and Pteromimus (Fig. 1). The palate is largely, if not entirely, unknown, but in Cosesaurus it is largely open with gracile elements.

What did Langobardisaurus eat?
The small size of Langobardisaurus omits nearly all possible prey items but insects and possibly smaller juvenile reptiles. The tricuspid teeth could have processed the hard exoskeletons of small invertebrates for more rapid assimilation. The rake-like “incisors” would have been good at grabbing tree-crawling insects. The bipedal posture and long neck would have made taller plants harboring insects more available.

Marine Sediments
Like Tanystropheus, Langobardisaurus was found in marine sediments. Was it washed in? Or a denizen of shallow waters? Likely washed in, like the one and only Cosesaurus, found stuck to a jellyfish.

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
Muscio G 1997. 
Preliminary note on a specimen of Prolacertiformes (Reptilia) from the Norian (Late Triassic) of Preone (Udine, north-eastern Italy). Gortania – Atti del Museo Friulano di Storia Naturale 18:33-40
Renesto S 1994. A new prolacertiform reptile from the Late Triassic of Northern Italy. Rivista di Paleontologia e Stratigrafia 100(2): 285-306.
Renesto S and Dalla Vecchia FM 2000. The unusual dentition and feeding habits of the Prolacertiform reptile Langobardisaurus (Late Triassic, Northern Italy). Journal of Vertebrate Paleontology 20: 3. 622-627.
Renesto S and Dalla Vecchia FM 2007. A revision of Langobardisaurus rossii Bizzarini and Muscio, 1995 from the Late Triassic of Friuli (Italy)*. Rivista di Paleontologia e Stratigrafia 113(2): 191-201. online pdf

wiki/Langobardisaurus

Now it’s Langobardisaurus and the Origin of the Pterosaur Sternal Complex

Earlier we discussed the evolution of the pterosaurian sternal complex beginning with the plesiomorphic basal tritosaur lizard, Huehuecuetzpalli, and continuing through Cosesaurus (Fig. 1). Though flightless, Cosesaurus had all the elements of a pterosaurian sternal complex in place: 1) strap-like scapula; 2) quadrant-shaped coracoid with stem attached to interclavicle anterior to the transverse processes; 3) cruciform interclavicle; 4) transverse clavicles rimming the broad sternum; 5) sternum and interclavicle layered and coincident. In pterosaurs the clavicles extend posteriorly along an initially triangular sternum and in most pterosaurs the coracoid stem straightens out. So it looks like Cosesaurus was flapping, but not flying.

The evolutionary leap from Huehuecuetzpalli to Cosesaurus was great, but not insurmountable. Now we find a transitional taxon between these two to better bridge that gap and provide data on the order of changes.  Some surprises and unexpected wonders are here that should open all new chapters on the origin of vertebrate flapping and flight.

langobardisaurus-pectoral-girdle

Today we reexamine Langobardisaurus tonelloi (Figs. 1-3), a close relative of Cosesaurus, Tanytrachelos and the long-necked giant, Tanystropheus. Langobardisaurus demonstrates a transitional phase in the evolution of the fenestrasaurian/pterosaurian pectoral girdle. 

The anterior dorsal area of Langobardisaurus tonneloi with original designations noted in black and new interpretations in color overlays.

Figure 2. Click to enlarge. The anterior dorsal area of Langobardisaurus tonelloi with original designations noted in black and new interpretations in color overlays. The original clavicle is now rib #9. The original coracoid is now the broad clavicle. The original scapula is now the coracoid. The original rib #10 (on the right) is now the strap-like scapula. Rib #10 (on the left) and the sternum were identified correctly. See below for a reconstruction and comparison.

New Interpretations of the Langobardisaurus pectoral elements
Renesto’s tracing of L. tonelloi (Fig. 2) included his interpretations based on what was known of sister taxa at the time, all of which were thought to have a Tanystropheus/Macrocnemus-like pectoral girdle with short broad, elliptical elements. Now Cosesaurus (Fig. 1) offers new possibilities. Here colorized to re-identify the elements (Fig. 2), the original coracoid is now the broad clavicle. The original scapula is now the coracoid. The original rib #10 (on the right) is now the strap-like scapula. Rib #10 (on the left) and the sternum were identified correctly. See below for a reconstruction and comparison.

Langobardisaurus tonneloi reconstructed. Note the cosesaur-like pectoral girdle.

Figure 3. Langobardisaurus tonelloi reconstructed. Note the cosesaur-like pectoral girdle. Click to learn more. The pes is also fenestrasaurian/pterosaurian in character.

Distinct from Cosesaurus
The coracoid in L. tonelloi did not develop an elongated stem. Otherwise the Cosesaurus and Langobardisaurus shared many pectoral shapes and arrangements.

The Shift
In order for the fenestrasaur pectoral girdle to develop, the coracoids had to move anterior to the interclavicle transverse processes. Langobardisaurus gives us that transitional mid-point. Remember the sternal complex was chiefly transverse in orientation while the the scapula/coracoid was largely parasagittal.

Bipedalism Frees up the Forelimbs
How the muscles shifted and why they shifted is still to be determined. A study by Renesto, Dalla Vecchia and Peters (2002) described the bipedal abilities of Langobardisaurus. When the forelimbs rise off the substrate, they are free to do other tasks. There’s the opportunity.

The coracoids do not appear to be locked in place in Langobardisaurus as they were in Cosesaurus, so pterosaur-like, bird-like flapping was not so well developed.

Chlamydosaurus, the Austrlian frill-neck lizard

Fig. 4 Chlamydosaurus, the Austrlian frill-neck lizard with an erect spine and elevated tail. Click to see a YouTube movie.

Hypothesis
As small insectivores, langobardisaurs and cosesaurs might have made tasty meals for larger predators. If similar in their bipedal abilities to the living lizard, Chlamydosaurus (Fig. 4), then bluff and charge might have been in their repertoire. Lacking expanding neck skin, langobardisaurs and cosesaurs might have charged bipedally frantically waving their forelimbs. This might have also impressed the girl langobardisaurs and if that’s deemed sexy, well, folks, you just get more of the same generation after generation.

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
Muscio G 1997. 
Preliminary note on a specimen of Prolacertiformes (Reptilia) from the Norian (Late Triassic) of Preone (Udine, north-eastern Italy). Gortania – Atti del Museo Friulano di Storia Naturale 18:33-40
Renesto S 1994. A new prolacertiform reptile from the Late Triassic of Northern Italy. Rivista di Paleontologia e Stratigrafia 100(2): 285-306.
Renesto S and Dalla Vecchia FM 2000. The unusual dentition and feeding habits of the Prolacertiform reptile Langobardisaurus (Late Triassic, Northern Italy). Journal of Vertebrate Paleontology 20: 3. 622-627.
Renesto S and Dalla Vecchia FM 2007. A revision of Langobardisaurus rossii Bizzarini and Muscio, 1995 from the Late Triassic of Friuli (Italy)*. Rivista di Paleontologia e Stratigrafia 113(2): 191-201. online pdf
Renesto S, Dalla Vecchia FM and Peters D 2002. Morphological evidence for bipedalism in the Late Triassic Prolacertiform reptile Langobardisaurus. Senckembergiana Lethaea 82(1): 95-106.

wiki/Langobardisaurus

Another Look at Amotosaurus

Amotosaurus

Figure 1. Amotosaurus reconstructed from data in Fraser and Rieppel (2006).

Amotosaurus rotfeldensis SMNS 50830 (Wild 1980) was originally considered a juvenile Tanystropheus antiquus, but Fraser and Rieppel (2006) determined that only eight cervicals were present, a shagreen of denticles covered the vomers, palatines and pterygoids, the second sacral rib was bifurcate, the tarsus was well-ossified and three distal tarsals were present. Due to the ossified tarsus they considered the small specimen an adult.

Ooops…
Unfortunately Fraser and Rieppel (2006) reported that Langobardisaurus had 12 rather than 8 cervicals and so missed an important shared trait. Here Amotosaurus nests with Langobardisaurus and they shared a longer mt 4 relative to mt 3 among several other characters. The scapula is much enlarged in Amotosaurus, as in Tanystropheus. The ventral pubis and ischium are in contact with one another, as in Cosesaurus, which also shares a longer metatarsal 4. The mandible is ventrally concave as in Langobardisaurus. The posterior teeth are difficult to see, but there seems to be little indication of anything but simple compressed cone shapes present, as in Tanystropheus. Pedal 5.1 was relatively shorter.

Protorosaur? No.
Protorosaurus nested near the base of the Archosauriformes. Langobardisaurus and Amotosaurusnested within the Lepidosauriformes, within the Tritosauria.

Why Ignore Langobardisaurus?
In their conclusion,  Fraser and Rieppel (2006) practically ignored Langobardisaurus. They reported, “At present it can be said that Amotosaurus probably occupies a position intermediate between Tanystropheus and Macrocnemus.” According to the present tree, that’s a position currently occupied by Langobardisaurus, here considered the closest sister of Amotosaurus and similar in size.

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
Fraser NC and Rieppel O 2006. A new protorosaur (Diapsida) from the upper Bundsandstein of the Black Forest, Germany. Journal of Vertebrate Paleontology 26(4):866-871.
Wild R 1980. Tanystropheus (Reptilia: Squamata) and its importance for stratigraphy. Mémoires de la Société Géologique de France, N.S. 139:201–206.