Tag Archives: cretaceous period

In ancient fish teeth, a tale of ecological resilience

Microscopic fish teeth may carry a message of hope from an ecological upheaval in the distant past, scientists at Yale University and the University of California-San Diego (UCSD) have found.

An analysis of tooth fossils and shark scales from the sea floor indicates that a massive die-off of species 66 million years ago did not, in fact, leave uniformly dead oceans around the world. In the Pacific Ocean, at least, some small fish species actually flourished. (more…)

Read More

Earliest birds lacked wide diversity of modern descendants, study finds

Birds come in astounding variety—from hummingbirds to emus—and behave in myriad ways: they soar the skies, swim the waters and forage the forests. But this wasn’t always the case, according to research by scientists at the University of Chicago and the Field Museum.

The researchers found a striking lack of diversity in the earliest known fossil bird fauna—a set of species that lived at about the same time and in the same habitat. “There were no swans, no swallows, no herons, nothing like that. They were pretty much all between a sparrow and a crow,” said Jonathan Mitchell, a PhD student in the Committee on Evolutionary Biology and lead author of the new study, published May 28 in Proceedings of the Royal Society B(more…)

Read More

Oldest existing lizard-like fossil hints at scaly origins

The fossilised remains of a reptile closely related to lizards are the oldest yet to be discovered.

Two new fossil jaws discovered in Vellberg, Germany provide the first direct evidence that the ancestors of lizards, snakes and tuatara (known collectively as lepidosaurs), were alive during the Middle Triassic period – around 240 million years ago.

The new fossil finds predate all other lepidosaur records by 12 million years. The findings are published in BMC Evolutionary Biology. (more…)

Read More

From a Few Bones, the Most Primitive Snake Emerges

Researchers at Yale have identified an ancient slithering creature from the time of T. rex as the most primitive known snake, a finding with implications for the debate over snake origins.

“It’s the missing-link snake,” said Nicholas Longrich, a postdoctoral fellow in Yale’s Department of Geology & Geophysics and the lead author of a paper about the lizard-like snake published July 25 online in the journal Nature. “It’s the ‘Lucy’ of snakes.”

The paper argues that snakes descend from terrestrial rather than marine ancestors, as recently proposed by others, and that snakes emerged once lizards developed long, limbless bodies for burrowing. (more…)

Read More

A Tailored Pair of Genes

*For ancient plants, two genes were definitely better than one*

In the wake of the disaster that killed the dinosaurs, the ancestors of today’s crop plants reinvented themselves.

They doubled their genomes, and in that single act set the stage for feeding the world 60 million years later.

In a study published in the Nov. 16 issue of the journal Nature, researchers from the University of Minnesota and other institutions recount how sequencing the genome of a model, alfalfa-like legume revealed the monumental benefits that flowed when the ancestor of legumes acquired an extra copy of every gene. (more…)

Read More

Worms Among First Animals To Surface After K-T Boundary Extinction Event, CU-Led Study Finds

A new study of sediments laid down shortly after an asteroid plowed into the Gulf of Mexico 65.5 million years ago, an event that is linked to widespread global extinctions including the demise of big dinosaurs, suggests that lowly worms may have been the first fauna to show themselves following the global catastrophe.

While the focus on the so-called K-T boundary extinction is often on the survival and proliferation of mammals, paleo-botanical studies show some of the earliest terrestrial ecosystems to emerge were dominated by low-diversity and opportunistic aquatic plants, said University of Colorado Boulder geological sciences Associate Professor Karen Chin. And while sediments laid down immediately following the impact event generally have relatively few animal fossils, new evidence from North Dakota shows networks of crisscrossing burrows less than three inches above the K-T boundary layer. (more…)

Read More

Primitive Birds Shared Dinosaurs’ Fate

A new study puts an end to the longstanding debate about how archaic birds went extinct, suggesting they were virtually wiped out by the same meteorite impact that put an end to dinosaurs 65 million years ago.

For decades, scientists have debated whether birds from the Cretaceous period — which are very different from today’s modern bird species — died out slowly or were killed suddenly by the Chicxulub meteorite. The uncertainty was due in part to the fact that very few fossil birds from the end of this era have been discovered. (more…)

Read More

New Species of Multi-horned Dinosaurs Unearthed in Utah

“A giant rhino with a ridiculously supersized head” 

“Fifteen long, pointed sideways oriented eye horns: one over the nose, one atop each eye, one at the tip of each cheek bone, and ten across the rear margin of the bony frill”

(more…)

Read More