Nibbling prehistoric herbivore sheds new light on Triassic diversity


Date:
November 29, 2021
Source:
University of Birmingham
Summary:
A Triassic herbivore, known for its supposed similarities to a
modern-day ostrich, has been revealed to have entirely different
approach to feeding from previously thought.



FULL STORY ==========================================================================
A Triassic herbivore, known for its supposed similarities to a modern-day ostrich, has been revealed to have entirely different approach to feeding
from previously thought, according to research at the University of
Birmingham.


==========================================================================
The new discovery reveals a much broader diversity of herbivore behaviour during the Triassic period than has been recognised to date.

Called Effigia, the animal was about the size of a gazelle and lived
in North America around 205 million years ago. Its fossil remains were
found in the Ghost Ranch Quarry in New Mexico in the 1940s, although
the material was not formally described by palaeontologists until 2006.

The remains had been relatively poorly preserved in the quarry and
the skull, in particular, was quite badly deformed, making accurate reconstruction problematic. Early analysis of the specimen concluded
that it belonged to the group of reptiles that includes crocodylians
and birds and which started to flourish in the Triassic period.

Although more closely related to crocodylians, Effigia'slightweight
body, elongated neck, large eyes and beak shared many similarities with
a modern-day ostrich, leading researchers to believe the animal fed by
pecking plant material from the ground.

But new analysis of the specimen, by experts at the University of
Birmingham, has revealed this animal was probably an entirely different
type of herbivore than previously thought. The work, carried out in
partnership with experts at the University of Bristol, University College London, University of York, Virginia Tech and the Natural History Museum,
is published in The Anatomical Record.

The team used new CT scans of Effigia'sskull which revealed a much more accurate reconstruction of the animal. This included new information
about the shape of the skull, such as a more rounded, bulbous brain
cavity and curved upper and lower jaws. Unlike an ostrich bill, which
is more rounded, Effigia's bill is more concave with jaws that open and
close a bit like a pair of shears.

The team used this information to model the effects of different forces
acting on the skull, including what happens when the animal pecks at
the ground. By modelling the forces the skull would need to withstand in
order to feed by pecking, the researchers calculated that Effigia'sskull
would probably have shattered. Instead, they suggest, the animal would
be more likely to use its jaws to snip off and nibble pieces of soft
plant material such as young shoots, or ferns.

Lead researcher, Dr Jordan Bestwick, said: "The herbivores we already
recognise in the Triassic period fed either by digging for roots,
such as the pig-like aetosaurs, or reaching for leaves high up in
the treetops, like the long-necked sauropods. These two-legged
browsers with a weak bite are unique to this period and show a
previously unrecognised diversity among the herbivores of this period." ========================================================================== Story Source: Materials provided by University_of_Birmingham. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Jordan Bestwick, Andrew S. Jones, Sterling J. Nesbitt, Stephan
Lautenschlager, Emily J. Rayfield, Andrew R. Cuff, David J. Button,
Paul M. Barrett, Laura B. Porro, Richard J. Butler. Cranial
functional morphology of the pseudosuchian Effigia and implications
for its ecological role in the Triassic. The Anatomical Record,
2021; DOI: 10.1002/ar.24827 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/11/211129105636.htm

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