Continuing problems in vertebrate paleontology – part 1

A quick glance through various paleontology topics
on various Wikipedia pages reveals a rather long list of antiquated views that remain as false paradigms. These were falsified by testing in the large reptile tree. We’ll just bring up a few of these at a time while waiting for more interesting paleo-news to break.

  1. The first amniotes, referred to as “basal amniotes”, resembled small lizards and evolved from the amphibian reptiliomorphs about 312 million years ago. Move that back to 340 mya for phylogenetically widespread fossil evidence of basal amniotes and to 360 mya for their hypothetical origins.
  2. The first dichotomy within the Amniotes produced the clades Synapsida and Sauropsida. In the LRT several amniote clades precede the advent of the Synapsida. The last common ancestors of all amniotes are Silvanerpeton and Gephyrostegus bohemicus. The first dichotomy produced the new Lepidosauromorpha and the new Archosauromorpha. Synapsids nest deeply within the new Archosauromorpha.
  3. Diadectomorpha is a clade of large reptile-like amphibians. The LRT nests all diadectomorphs deep within the new Lepidosauromorpha. 
Figure 1. A new reconstruction of Gephyrostegus bohemicus. This species lived 30 million years after the origin of the Amniota in the Visean, 340 mya. Note the lack of posterior dorsal ribs. This trait shared by all basalmost amniotes, may provide additional space for massive eggs in gravid females, but is also shared with males, if there were males back then.

Figure 1. A new reconstruction of Gephyrostegus bohemicus, a late-surviving basalmost amniote. This species lived 30 million years after the other amniotes in the Visean, 340 mya. Note the lack of posterior dorsal ribs. This trait shared by all basalmost amniotes, may provide additional space for massive eggs in gravid females, but is known in all specimens.

And while we’re at it…
This comes courtesy of Ben Creisler at the DML TheSociety of Vertebrate Paleontology 2016 Meeting Program and Abstract Book is available here:

PLEASE NOTE! Content is embargoed until the actual presentation.
“Unless specified otherwise, coverage of abstracts presented orally at the Annual Meeting is strictly prohibited until the start time of the presentation, and coverage of poster presentations is prohibited until the relevant poster session opens for viewing.”
There is one abstract in there
that confirms something I discovered four years ago, which brings some satisfaction that it was discovered again.

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