January/February 2019^ DISCOVER^67
FROM TOP: MING BAI, CHINESE ACADEMY OF SCIENCES; VELIZAR SIMEONOVSKI/THE FIELD MUSEUM; ANASTASIIA CHERNIAVSKAIA/SHUTTERSTOCK; MING BAI, CHINESE ACADEMY OF SCIENCES
Snakes Alive! Amber
Preserves a Big-Deal Baby
A lump of amber from northern Myanmar is
small enough to fit in your hand but holds
outsized scientific significance: a tiny snake,
preserved for about 100 million years.
“It’s got a lot of -ests,” says University of
Alberta paleontologist Michael Caldwell, a co-
author on the July Science Advances paper describing the find.
Xiaophis myanmarensis is the oldest snake of any age preserved in
amber, and, at less than 2 inches long, it’s the only baby snake in the entire
fossil record. It’s also the earliest forest-dwelling snake known; insects and
vegetation preserved with it provided clues to its environment.
Little Xiaophis appears most similar to ancient snakes in South Africa and
South America, rather than geographically closer marine snakes, making
it the first hint of an ancient lineage that spread, or radiated, across the
supercontinent Gondwana. Says Caldwell: “The connection to an ancient
Southern Hemisphere radiation is not something we’d ever predicted.”
Using different imaging techniques, the team created a 3D reconstruction
of the entire skeleton that could be viewed on a “nano level” — another first
for ancient snake studies.
“We can see similarities and differences in the development between
this ancient lineage and modern snakes,” says Caldwell. “It is unbelievably
powerful to be able to see those details. You just don’t get development
[preserved] in the rock fossil record.”Dinosaur Sported
Iridescent Feathers
A 160 million-year-
old feathered
dinosaur from
northeastern
China
may have
shimmered
like modern
hummingbirds.
Researchers
describing
Caihong juji in
Nature Communications
in January found vestiges of its
melanosomes, cellular structures that,
in feathers and skin, can determine
pigmentation patterns. Comparing
Caihong’s melanosomes with those
of modern birds, the team concluded
that the flashy dino had multicolored,
iridescent feathers on its head, tail
and wings.
Using fossilized melanosomes to
determine what extinct animals may
have looked like is a growing trend, but
in July another Nature Communications
study urged caution. Melanosomes occur
throughout the body, not just in the
skin and feathers, and can shift around
during decomposition, making it tough
to determine an animal’s true colors.Origins of the First
American Pooches
Did the first humans to reach the New
World bring dogs with them from Siberia
or domesticate local wolves after arrival?
According to a
large-scale analysis
of ancient and
modern doggie
DNA published
in Science in
July — part of
an ongoing
international
project to
understand
our best friends’
origins — the earliest
American dogs were closely related to
Siberian populations. The study turned up
no evidence that New World wolves were
domesticated by First Americans. Alas,
the story doesn’t end well: Later waves
of European dogs genetically wiped out
the Americas’ first Fidos.FURTHER AFIELD
Preserved for 100 million years
in amber, this baby snake is
unique in the fossil record.Researchers were able to
create a three-dimensional,
extremely high-resolution
model of the 100 million-
year-old snake using X-ray
micro-CT scanning.