[The title
was written by my editor.]
Researchers discover a basal ichthyosauriform fossil in China that is
thought to be from the upper Lower Triassic period, the skeleton of which
suggests it was amphibious.
by John
Tyburski
Copyright © Daily
Digest News, KPR Media, LLC. All rights reserved.
An
international team of researchers claim they have the missing link between a
prehistoric aquatic predator and its even older land-dwelling ancestors. The
fossil has a body form that suggests it exhibited amphibian-like behavior and
is thought to link Ichthyosaurs to their terrestrial ancestors. The find is
said to be problematic for creationists, or those who reject the prevailing
naturalistic explanation for how life originated and evolved on Earth.
Paleontologists
have long argued that Ichthyosaurs evolved from land-dwelling ancestors as they
returned back to aquatic environments over time. However, fossils showing
stages of this transition have been lacking. A new report
published on Wednesday in the journal Nature describes a putative intermediate
fossil of an amphibious ancestor of the water-dwelling Ichthyosaurs called Cartorhynchus lenticarpus.
“Many
creationists have tried to portray ichthyosaurs as being contrary to
evolution,” said lead author Ryosuke Motani, a professor of earth and planetary
sciences at the University of California Davis. “We knew based on their bone
structure that they were reptiles, and that their ancestors lived on land at
some time, but they were fully adapted to life in the water. So creationists
would say, well, they couldn’t have evolved from those reptiles, because
where’s the link?”
Montani
and colleagues from around the globe found the fossil in the Anhui Province of
China back in 2011 but were not certain how to classify it. The creature
appears to have lived 248 million years ago and measured about 18 inches long.
“Initially
I was really puzzled by this fossil,” Motani said. “I could tell it was related
[to ichthyosaurs], but I didn’t know how to place it. It took me about a year
before I was sure I had no doubts.”
Because
the fossil shows signs of neither adaptation to aquatic nor terrestrial life,
the researchers concluded it must be of an amphibious creature. The bones and
flippers of this fossil suggest time spent on both land and in water during a
period roughly four million years after a mass extinction of dinosaurs.
“This
animal probably had a happy life. It was in the tropics, and it was probably a
bottom feeder that fed on soft-bodied things like squid and animals like
shrimp,” Motani said. “And for a predator like that to exist, there has to be
plenty of prey. This was probably one of the first predators to appear after
that extinction.”
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