Archives par mot-clé : Paleontology

David Attenborough gets a namesake: the oldest known relative of living animals

by T. Joose,  July 25, 2022, in Science


If you visited the oceans more than 500 million years ago, you’d find yourself in an alien world. Beings with quilted folds of soft tissue sat on the seabed like rugs, and life forms that looked like fronded plants but were actually animals made anchor on the ocean floor. But one organism might be somewhat familiar: a stalked, cuplike creature with waving tentacles resembling those of a jellyfish. The newly described fossil of this organism, named Auroralumina attenboroughiiafter naturalist and broadcaster David Attenborough, is between 556 million and 562 million years old and may be the oldest example of an evolutionary group still living today.

When co-author and University of Oxford paleobiologist Frances Dunn saw a cast of the fossil, she says, “It was instantly clear that this was really special and really rare.” With other fossils from the Ediacaran period, between 635 million and 541 million years ago, her first impression often is “What is this? How can I relate this to anything that’s alive today?” But with this specimen, she thought, “I know what this is.”

Classical scientific wisdom places the origin of modern animals about 539 million years ago during what’s called the Cambrian explosion. At this time, creatures with specialized tissues, organs, guts, and symmetrical left and right sides—all traits we recognize in the animals of today—began popping up.

A voracious Cambrian predator, Cambroraster, is a new species from the Burgess Shale

by Royal Ontario Museum, July 31, 2019 in ScienceDaily


Fossils of a large new predatory species in half-a-billion-year-old rocks have been uncovered from Kootenay National Park in the Canadian Rockies. This new species has rake-like claws and a pineapple-slice-shaped mouth at the front of an enormous head, and it sheds light on the diversity of the earliest relatives of insects, crabs, spiders, and their kin.

Reaching up to a foot in length, the new species, named Cambroraster falcatus, comes from the famous 506-million-year-old Burgess Shale. “Its size would have been even more impressive at the time it was alive, as most animals living during the Cambrian Period were smaller than your little finger,” said Joe Moysiuk, a graduate student based at the Royal Ontario Museum who led the study as part of his PhD research in Ecology & Evolutionary Biology at the University of Toronto. Cambroraster was a distant cousin of the iconic Anomalocaris, the top predator living in the seas at that time, but it seems to have been feeding in a radically different way,” continued Moysiuk.

Rare fossil in a fossil reveals a dinosaur’s surprising last meal

by Michael Gresko, July 11, 2019 in NationalGeographic


The find—described today in the journal Current Biology—is the fourth Microraptor fossil to preserve stomach contents, but it’s the first to show that Microraptor ate lizards. Previous fossils captured it eating small mammals, fish, or birds. The specimen also reveals that, like some predatory birds today, Microraptor had a taste for swallowing lizards whole and head-first.

This fossil of the feathered dinosaur Microraptor also preserves the animal’s last meal: a lizard it seems to have swallowed whole and head first.

PHOTOGRAPH BY XUWEI YIN

Remember when were told sea creatures couldn’t run from global warming? Never mind.

by Anthony Watts, may 17, 2018 in WUWT


By investigating fossils, Prof. Kießling and Dr. Carl Reddin, who is also at GeoZentrum Nordbayern, have shown that coral, molluscs, and sponges have been following their preferred cold and warm zones for half a billion years. Isotherms (geographic lines denoting the same temperature, for example 20°C) shift towards the poles or the equator as soon as the global temperature rises or decreases. Isotherms have been shifting towards the poles for several years due to global warming.

The tendency towards climate-related migration is most apparent in tropical species. This may be due to the fact that several of these species live near the thermal maximum for complex organisms of 35-45°C . Current global warming trends are driving marine animals towards the poles, provided there is a suitable habitat they can migrate to.