DGS applied to Batrachognathus (anurognathid pterosaur)

Batrachognathus volans (Figs. 1, 2) is a derived anurognathid pterosaur with large binocular eyes and a very short metacarpus. Many of the bones are preserved as bones. Others are preserved as ephemeral impressions. This roadkill fossil (Fig. 2) can be interpreted with clarity using DGS (digital graphic segregation), a falsely maligned method of tracing crushed in situ fossils from photographs in use by many paleontologists.

Figure 3. Batrachognathus volans recontructed. Note the tail is not half again as long as the humerus and not provided with stiffening spines, casting doubt on the identification of the Costa specimen.

Figure 3. Batrachognathus volans recontructed. Note the tail is not half again as long as the humerus and not provided with stiffening spines, casting doubt on the identification of the Costa specimen.

Below
is the in situ specimen, PIN 13, of Batrachognathus. Every five seconds a tracing overlaps the original image. Each color represents a different bone and these colors were transferred to the reconstruction (Fig. 1), assuring accuracy. All the parts fit like parts in a model airplane. All the parts match sister taxa. When left and right parts are present, they match.

Fig 2. GIF animation of Batrachognathus with tracings of bones over the bones and their impressions.

Fig 2. GIF animation of Batrachognathus with tracings of bones over the bones and their impressions. While some bones are easy to discern, others are not and the chaos of this specimen needs segregation and simplification to understand it. In a reconstruction all the parts fit and match left to right.

If DGS can be successfully used here
(Fig. 2) it can be used on other specimens as well. There is no need to avoid this technique if you want to understand a fossil more fully. Yes, you should listen to the worries and fears of the data deniers, then decide for yourself after trying the DGS technique yourself.

References
Bakhurina NN 1988. [On the first rhamphorhynchoid from Asia: Batrachognathus volansRiabinin 1948, from Tatal, western Mongolia]. Abstract of paper in Bulletin of the Moscow Society for the Study of Natural History, Geological Section 59(3): 130 [In Russian].
Rjabinin AN 1948. Remarks on a Flying Reptile from the Jurassic of Kara-Tau. Akademia Nauk, Paleontological Institute, Trudy 15(1): 86-93.

wiki/Batrachognathus

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