Tapejara (Pterosaur) Growth Pattern

The traditional paradigm is that pterosaurs experienced allometric growth, like mammals, birds and crocodilians. If so the rostrum should be shorter and the eye sockets (orbits) should be proportionally larger.

The heretical view holds that pterosaurs experienced isometric growth with little proportional differences in embryos, juveniles and adults. Currently this is supported by the evidence of embryos and the few juveniles known, including Tupuxuara.

Now we have another juvenile, a Tapejara. Here (Fig. 1) the published tracings of the juvenile Tapejara have been enlarged to best fit the adult Tapejara. Here the proportions are virtually identical, with no rostral shortening or orbit enlargement. The main difference is the depth of the nasal and the angle of the jaw.

Tapejara (Pterosaur) growth patterns

Figure 1. Tapejara (Pterosaur) growth patterns demonstrating, once again, isometric growth in which virtually no proportional differences distinguish juveniles from adults. In grey, the juvenile to scale with an adult. Overlay, the juvenile enlarged to the size of the adult. The depth of the nasal, over the orbit, appears to be the biggest difference here, but then again we’re dealing with drawings here. Could that nasal be rotated slightly?

Go with the evidence. Don’t follow traditions and paradigms.

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.

Eck K, Elgin RA and Frey E 2011.
 On the osteology of Tapejara wellnhoferi KELLNER 1989 and the first occurrence of a multiple specimen assemblage from the Santana Formation, Araripe Basin, NE-Brazil. Swiss Journal of Palaeontology, doi:10.1007/s13358-011-0024-5.
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.


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