A rare horned dinosaur fossil shows species on North America

[frigidmagi]

Mirror

A rare horned dinosaur fossil shows species on North America’s east and west coasts ate differently.

The bone fragment reveals the dog-sized creature – from the eastern area of Appalachia – had teeth that curved downwards and outwards, and a more slender beak-like jaw than its western relatives, showing that their diets differed.

This adds to the theory that North America was split into two continents by water 66 to 100 million years ago, so dinosaurs on each side evolved separately.

Dr Nick Longrich, from the University of Bath’s Milner Centre for Evolution studied the specimen.

He said: “Each one of these island continents would have evolved its own unique dinosaurs, so there are probably many more species out there.”

When the sea levels were very high and the landmasses across the Earth were very fragmented, is like looking at several independent experiments in dinosaur evolution.downward and outwards in a beak shape.

The jaw was also more slender than that of Ceratopsia found in western North America, suggesting the dinosaurs had different diets and evolved along distinct evolutionary paths.

“Just as many animals and plants found in Australia today are quite different to those found in other parts of the world, it seems that animals in the eastern part of North America in the Late Cretaceous period evolved in a completely different way to those found in the western part of what is now North America due to a long period of isolation,” Dr Longrich said.

“This adds to the theory that these two land masses were separated by a stretch of water, stopping animals from moving between them, causing the animals in Appalachia to evolve in a completely different direction, resulting in some pretty weird looking dinosaurs.

“Studying fossils from this period, when the sea levels were very high and the landmasses across the Earth were very fragmented, is like looking at several independent experiments in dinosaur evolution.

“At the time, many land masses - eastern North America, Europe, Africa, South America, India, and Australia - were isolated by water.

“Each one of these island continents would have evolved its own unique dinosaurs - so there are probably many more species out there to find.”

Ceratopsia is a group of plant-eating horned dinosaurs that lived in the Cretaceous period.

The fossil Dr Longrich studied comes from a smaller cousin of the better known Triceratops, the leptoceratopsids - about the size of a large dog.

His study, published in the journal Cretaceous Research, highlights it as the first fossil from a ceratopsian dinosaur identified from this period of eastern North America.

[LadyTevar]

There are several reasons why we have not found many Eastern US dinosaur fossils.

First, unlike the Western US, the Appalachias had been standing since the Triassic era, formed as Pangaea separated. By the Cretaceous Period, when this dog-like dino was living, the Appalachias were larger than the Rockies, and possibly had peaks equal to the Himalayas. When the Ice Age hit, glacers destroyed the over half of the Appalachia fossil records, literally eating them away from the mountainsides. Gradual erosion took care of the rest.

Second, the scientists of the 1800s had little interest in what fossils might lie in the Appalachian Mountains, outside of plant life and the early fossiils found embedded in coal, salt, and limestone deposits. Even today, what fossils we do have from the Appalachian beds are often under-studied; mis-labelled, mis-named, and forgotten in the wake of the more interesting dino fossils found in the Western US.

Finally, the majority of dinosaur bones across the world are found in places where plant-life is scarse or patchy, and the bones are literally being eroded out of the bare earth. The Appalachias, however, are densely covered with plant-life, which both holds the soil in place and hides what bones may lie underneath, giving palentologists very few exposures to reach and explore. However, large sites like the Selma Formation, spread across the Southern Appalachias, where chalk sands have revealed a surprisingly large amount of dino and non-dino fossils no one ever talks about ... like the Appalachiosaurus, a tyranosaursoid theropod. Other non-dino fossils are thick in this formation, revealling cartilignious fish, bony fish, reptiles, moarasaurs, and crocodillians.

I personally believe that thousands of fossils have been systematically destroyed over the years by mining, and the current trend of Mountaintop Removal is the worst offender. Half the mountain blown off, then the non-coal bulldozed into the nearest valley -- who knows what bones may have been in those layers? The mining companies won't bother to check, a bone-bed -- human or otherwise -- only gets in the way of Profits. A newly discovered gravesite can shut down a mining operation for weeks as its investigated. A full-fledged dino graveyard would put a mining company out of business in that area.