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.)

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s