Kellner et al. 2019
bring us a new desert pterosaur, Keresdrakon (Fig. 1). The bone is exceptionally preserved, similar to red bed Gobi Desert specimens from the Late Cretaceous. The exact age of the strata is “controversial.” Kellner et al. nest their new specimen between Dsungaripteridae + Shenzhoupterus and Tapejaridae (omitting the unrelated Chaoyangopteridae + Azhdarchidae, see below).
From the abstract:
“Here we present a new tapejaromorph flying reptile from this site, Keresdrakon vilsoni gen. et sp. nov., which shows a unique blunt ridge on the dorsal surface of the posterior end of the dentary. Morphological and osteohistological features indicate that all recovered individuals represent late juveniles or sub-adults. This site shows the first direct evidence of sympatry in Pterosauria. The two distinct flying reptiles coexisted with a theropod dinosaur, providing a rare glimpse of a paleobiological community from a Cretaceous desert.”
Sympatry: “Occupying the same or overlapping geographic areas.” I have used the term ‘coeval’ to represent taxa from a similar formation (location and strata).
The same desert strata ‘cemetary of pterosaurs’
produced many partial specimens and several ontogenetic ages of the tapejarid, Caiuajara, which we looked at earlier here.
Figure 1. The larger bits and pieces of Keresdrakon. The bone is like bone, clearly distinct from the desert matrix.
Unfortunately
Kellner et al. have excluded so many pterosaur taxa from their cladogram that it does not recover the four origins of pterodactyloid-grade pterosaurs known for the last 12 years (Peters 2007) and documented online in the large pterosaur tree (LPT, 239 taxa). Instead the authors follow the traditional, invalidated hypothesis that includes a monophyletic and awkward ‘Pterodactyloidea.’ that is only recovered by taxon exclusion.
Remember,
dsungaripterids, tapejarids and pteranodontids all arise from various germanodactylids, which arise from pterodactylids, which arise from a branch of tiny scaphognathids. Ornithocheirds + cycnorhamphids arise from other tiny scaphognathids. Ctenochasmatids arise from one branch of dorygnathids. Azhdarchids arise from yet another branch of dorygnathids. All had tiny transitional pterosaur ancestors. Sadly, this is completely lost on the Kellner team, who have chosen to omit pertinent taxa from their analyses.
Otherwise
their topology is similar enough to the LPT. I have not yet entered Keresdrakon into the LRT. If the nesting differs from that of Kellner et al. (above), I will post that.
References
Kellner AWA, Weinschuütz LC, Holgado B, Bantim RAM and Sayão JM 2019. A new toothless pterosaur (Pterodactyloidea) from Southern Brazil with insights into the paleoecology of a Cretaceous desert. Anais da Academia Brasileira de Ciências (2019) 91(Suppl. 2): e20190768 (Annals of the Brazilian Academy of Sciences).
Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.
The Pterosaur Heresies 