New Postcranial Tapejara Material Reported
Tapejara was an Early Cretacous pterosaur known from several crested skulls, but post-cranial material has not been published. A recent paper on some post-cranial material and a mandible of Tapejara (Elgin and Campos 2011) included some “incomplete” pedal material. The study of pterosaur feet has been a specialty (Peters 2000, 2010, 2011), so recovering more data from this fossil was deemed important.
Elgin and Campos (2011) traced the fossil (SMNK PAL 3986) and reported three metatarsals, four proximal phalanges, one distal phalanx and one ungual (Figure 1.)
DGS – Digital Graphic Segregation
One of the authors (Herbert Bruno Campos) was kind enough to send me a jpeg of the fossil upon which I was able to trace using the much maligned Photoshop and DGS (Digital Graphic Segregation) method. The DGS tracing revealed several additional elements, essentially all the remaining phalanges and unguals plus a fourth and fifth metatarsal (mt 3 and mt 5, Figure 2).
Digitally shifting the colored elements into their original positions (Figure 3) recovers a pes with unguals 2-4 aligned. Discontinuous PILs can be drawn through digits 2-4 that intersect p1.1.
Comparison to Other Pterosaurs
The new Tapejara foot reconstruction demonstrates many similarities with other sister taxa feet (Figure 4). These also had discontinuous PILs that intersected p1.1 and several aligned unguals 2-4. This lends confidence to the identification, tracing and reconstruction of the Tapejara elements.
Filling in the Gaps
Pterosaur feet are rarely studied and reconstructed, so this exercise added to our knowledge of this clade. The DGS method using a photograph provided more data than original observation. The reconstruction was tested by comparisons to sister taxa.
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.
Elgin RA and Campos HBN 2011. A new specimen of the azhdarchoid pterosaur Tapejara wellnhoferi. Historical Biology (advance online publication) DOI:10.1080/08912963.2011.613467
Peters D 2000a. Description and Interpretation of Interphalangeal Lines in Tetrapods. Ichnos 7:11-41.
Peters D 2010. In defence of parallel interphalangeal lines. Historical Biology iFirst article, 2010, 1–6 DOI: 10.1080/08912961003663500
Peters D 2011. A Catalog of Pterosaur Pedes for Trackmaker Identification
Ichnos 18(2):114-141. http://dx.doi.org/10.1080/10420940.2011.573605