My what big teeth you have!! Introducing Guidraco

Guidraco venator (Wang et al., 2012) IVPP V17083, ~38 cm skull length, is a new crested ornithocheirid from the Lower Cretaceous of China. It was correctly nested as a sister to Ludodactylus and shared many traits with it and its many toothed South American sisters, like Anhanguera and Cearadactylus, but Guidraco is also a more distant sister to Liaoningopterus from ChinaAn upright crest and enormous anterior teeth set Guidraco apart from the others.

Guidraco in situ

Figure 1. Guidraco in situ from Wang et al. 2012. The extent of the parietal shown here may have something to do with a displaced underlying bone, like a postorbital creating an outline.

Guidraco was so well preserved that very little reconstruction is necessary. The upper temporal fenestra was large, probably in association with the enlargement of the premaxillary teeth, probably to oppose the pulling vectors brought on by the teeth during prey capture. In ornithocheirid skulls bones often fuse together obliterating sutures. Some of these identifications are based on comparisons to sister taxa.

Guidraco skull reconstructed.

Figure 2. Guidraco skull reconstructed. Not changes with the original in figure 3.

Original Reconstruction
The reconstruction by Wang et al. 2012 includes minor difference from the present reconstruction. Contra the original reconstruction, the premaxilla includes four teeth, including the medial nubbin. The nasal extends further than originally reconstructed, laminated beneath the premaxilla. A stem-like nasal process was present in the antorbital fenestra. Vestigial nares (primary and secondary were present) attended by anterior laminated extensions of the jugal and nasal. The quadratojugal extended up the lateral quadrate, as in other pterosaurs. The upper temporal fenestra and parietal were taller. This matches the shape of the occiput. The postorbital overlapped the squamosal as in other pterosaurs. A postfrontal is present. The sclerotic ring was not so robust.

Original reconstruction by Wang et al. (2012).

Figure 3. Original reconstruction by Wang et al. (2012). Please note several distances.

A Pteranodontoid?
Wang et al. (2012) nested Guidraco and all other ornithocheirids with Pteranodon in a clade called Pteranodontoidea. This odd nesting of toothless with toothy taxa is a product of taxon exclusion. When more taxa are included, as in the large pterosaur tree, ALL the pterosaurs with a pointed rostrum nest together and apart from the toothy ornithocheirids, who find more parsimonious sister nestings with Cycnorhamphus and Scaphognathus, along with several tiny pterosaur intermediates.

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.

Wang X-L, Kellner AWA, Jiang S-X and Cheng X 2012. New toothed flying reptile from Asia: close similarities between early Cretaceous pterosaur faunas from China and Brazil. Naturwissenschaften in press. doi:10.1007/s00114-012-0889-1.



Leave a Reply

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

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

Facebook photo

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

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.