Snapshot of the past
Amber-trapped lizard fossils reveal lost world:
Lizards locked in amber for 99 million years give a glimpse of a
‘lost world,’ say scientists. The ancient reptiles are preserved in
‘superb detail’ down to scales of skin, the tip of a tongue and tiny
claws.
Two of the fossils are related to modern-day chameleons and geckos,
revealing how features such as sticky toe-pads evolved.
The lizards inhabited tropical forests in what is now Myanmar during
the Mid-Cretaceous Period. Researchers in the US have published their
assessment of the specimens in the journal Science Advances.
“The fossilized amber provides a view into a lost world, revealing
that the tropics of the Mid-Cretaceous contained a diverse lizard
fauna,” Dr. Edward Stanley of the Florida Museum of Natural History told
BBC News. Some of the lizards are representatives of modern groups such
as geckos, while others have no modern equivalent and eventually died
out.One of the fossils appears to be a transitional form between the
‘standard’ lizard form and chameleons, said Dr Stanley.
“This ‘missing-link’ is roughly 80 million years older than the next
oldest chameleon fossil, and shows that features like the chameleon’s
projectile tongue was present deep in its ancestry,” he added.
“But the strange-fused toes (adaptations for climbing along
branches), evolved later.”
The amber fossils were obtained by private collectors and were
acquired by museums in the US. They have now been collated and studied
for the first time.
“They provide details of external morphology, which is something that
is pretty rare to find,” said Juan Diego Daza, of Sam Houston State
University in Texas, who led the research. “These fossils represent most
of the diversity of lizards with a superb amount of detail.”
Soft tissues and internal organs – as well as bones – can persist in
amber for millions of years.
“We can pretty much see how the animals looked when they were alive,”
explained Prof Daza.
“They provide a really nice snapshot of the past. To me it is like
going back in time and doing a lizard collecting trip when we can see
what these animals looked like.”
Some of the smaller specimens are whole lizards but others are
fragments of animals.
Together, they could resolve some of the gaps in the family tree
between ancient reptiles and their modern relatives.
-BBC
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