Where’s FAILblog when we need it? This self-parody is from that science-fantasy classic, the Atlas of Creation:
The Big Book o’ Creationist Nonsense claims that the fossil on the left is a frog from 280 million years ago that is identical to a modern frog. Unfortunately for that claim, the fossil’s tail and short legs are clearly visible.
It looks as if Karaurus comes from here. In fact, it is A 150-million-year-old salamander fossil showing frog-like skeletal elements, such as a broad, enlarged head. It has been identified as Karaurus, which is from the Kimmeridgian in the Late Jurassic, between 150 and 155 megayears old.
As you can see, they’ve lightened up the image quite a bit and for some reason reversed left for right. I suppose that’s artistic licence, not quite as ridiculous as when the publishers included a picture of an artificial lure instead of an actual insect to illustrate a point of biology.
If it were a Permian fossil, it would have looked much more like the one described here, Gerobatrachus hottoni: Frog-salamander split found.
An Early Permian landscape, with Gerobatrachus hottoni lunging at the mayfly Protoreisma
The examination and detailed description of the fossil (Hotton’s elder frog) settles the dispute whether frogs and salamanders evolved from an ancient amphibian group called temnospondyls.
According to a press release garbled at eurekalert,
The dispute arose because of a lack of transitional forms. This fossil fills the gap, according to Jason Anderson, assistant professor, University of Calgary Faculty of Veterinary Medicine, and lead scientist in the study.
The Gerobatrachus fossil provides a much fuller understanding of the origin and evolution of modern amphibians. The skull, backbone and teeth of Gerobatrachus have a mixture of frog and salamander features: the fossil has two fused bones in the ankle, which is normally seen only in salamanders, and a very large tympanic ear (eardrum). It also has a lightly built and wide skull like that of a frog.
Its backbone is exactly intermediate in number [of vertebrae] between [choose one, article is unclear]:
- EITHER the modern frogs & salamanders vs. the more primitive amphibians
- OR the modern frogs vs. the salamanders & more primitive amphibians.
The new fossil also addresses a controversy over molecular clock estimates, or the general time salamanders and frogs evolved into two distinct groups.
“With this new data our best estimate indicates that frogs and salamanders separated from each other sometime between 240 and 275 million years ago, much more recently than previous molecular data had suggested,” says Robert Reisz, professor, University of Toronto Mississauga and second author on the paper.
Gerobatrachus was originally discovered in Texas in 1995 by a field party from the Smithsonian Institution that included the late Nicholas Hotton, for whom the fossil is named. It remained unstudied until it was “rediscovered” by Anderson’s team. [Hotton never got around to studying it before he died and it was his to do.] It took countless hours of work on the small, extremely delicate fossil to remove the overlying layers of rock and uncover the bones to reveal the anatomy of the spectacular looking skeleton.
Caption: An Early Permian landscape, with Gerobatrachus hottoni lunging at the mayfly Protoreisma between stands of Calamites and under a fallen Walchia conifer.
Image credit: Michael Skrepnick