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All
teeth and claws? New study sheds light on dinosaur claw function
Date:
May 6, 2014
Source:
University of Bristol
Summary:
How claw form and function changed during the
evolution from dinosaurs to birds is explored in a new study into the claws of
a group of theropod dinosaurs known as therizinosaurs. Theropod dinosaurs, a
group which includes such famous species as Tyrannosaurus rex and Velociraptor,
are often regarded as carnivorous and predatory animals, using their sharp
teeth and claws to capture and dispatch prey. However, a detailed look at the
claws on their forelimbs revealed that the form and shape of theropod claws are
highly variable and might also have been used for other tasks
.............................
Theropod dinosaurs, a group which includes such famous
species as Tyrannosaurus
rex and Velociraptor,
are often regarded as carnivorous and predatory animals, using their sharp
teeth and claws to capture and dispatch prey. However, a detailed look at the
claws on their forelimbs revealed that the form and shape of theropod claws are
highly variable and might also have been used for other tasks.
Inspired by
this broad spectrum of claw morphologies, Dr Stephan Lautenschlager from
Bristol's School of Earth Sciences studied the differences in claw shape and
how these are related to different functions.
His research
focussed on the therizinosaurs, an unusual group of theropods which lived
between 145 and 66 million years ago. Therizinosaurs were very large animals,
up to 7m tall, with claws more than 50cm long on their forelimbs, elongated
necks and a coat of primitive, down-like feathers along their bodies. But in
spite of their bizarre appearance, therizinosaurs were peaceful herbivores.
Dr
Lautenschlager said: "Theropod dinosaurs were all bipedal, which means
their forelimbs were no longer involved in walking as in other dinosaurs. This
allowed them to develop a whole new suite of claw shapes adapted to different
functions."
In order to
fully understand how these different claws on the forelimbs were used, detailed
computer models were created to simulate a variety of possible functions for
different species and claw morphologies.
The dinosaur
claws were also compared to the claws of mammals, still alive today, whose
function (that is, how and for what the claws are used) is already known.
In the
course of evolution, several theropod groups, including therizinosaurs, changed
from being carnivores to become plant-eaters. This new study reveals that,
during this transition, theropod dinosaurs developed a large variety of claw
shapes adapted to specific functions, such as digging, grasping or piercing.
Dr
Lautenschlager said: "It's fascinating to see that, with the shift from a
carnivorous to a plant-based diet, we find a large variety of claw shapes adapted
to different functions. This suggests that dietary adaptations were an
important driver during the evolution of theropod dinosaurs and their
transition to modern birds."
Story
Source:
The above
story is based on materials provided by University of Bristol. Note: Materials may be
edited for content and length.
Journal
Reference:
- Paper Stephan Lautenschlager. Morphological and functional diversity in therizinosaur claws and the implications for theropod claw evolution. Proceedings of the Royal Society B, 2014
Cite This
Page:
University of Bristol. "All teeth
and claws? New study sheds light on dinosaur claw function." ScienceDaily.
ScienceDaily, 6 May 2014.
<www.sciencedaily.com/releases/2014/05/140506204105.htm>.