Wednesday, October 20News That Matters
Shadow

Tag: Paleontologists

New fossil helps paleontologists decipher evolutionary history of caimans, alligators

New fossil helps paleontologists decipher evolutionary history of caimans, alligators

Science
Jan. 15 (UPI) -- Alligators and caimans are closely related, but their evolutionary history is complicated. And because the two groups look so similar, untangling their evolving relations across time and space has proven especially difficult for paleontologists. Advertisement Thankfully, a new fossil, described Friday in the journal PeerJ, has offered scientists insights into the history of Alligatoridae family, the group of crocodylians that includes alligators and caimans. The fossil, a partial skull, was originally unearthed in 2010 at a dig site in Far West Texas, a mountainous region of the Chihuahuan Desert. Far West Texas, or Trans-Pecos Texas, is home to what's known as the Devil's Graveyard Formation. It's a geologic formation preserving fossils from the latter half of the Eocen...
Paleontologists find evidence of new mass extinction 233 million years ago

Paleontologists find evidence of new mass extinction 233 million years ago

Science
Sept. 16 (UPI) -- Paleontologists have unearthed evidence of a new mass extinction that occurred during the Late Triassic, some 233 million years ago. The extinction event, which scientists dubbed Carnian Pluvial Episode, was characterized by significant reductions in biodiversity and the loss of 33 percent of marine genera. Advertisement In a new paper, published Wednesday in the journal Science Advances, researchers suggest the episode may have created the ecological space for the emergence of a variety of important modern plant and animal lineages -- including conifers, insects, dinosaurs, crocodiles, lizards, turtles and mammals. Through analysis of both paleontological assemblages and geological evidence, researchers confirmed that biodiversity declines coincided with stark chemical ...
Paleontologists find giant lizard in stomach of a prehistoric marine carnivore

Paleontologists find giant lizard in stomach of a prehistoric marine carnivore

Science
Aug. 20 (UPI) -- Until now, scientists thought ichthyosaurs -- the large, dolphin-like marine reptiles that cruised the seas of the Mesozoic -- mostly ate cephalopods. "Many of the large ichthyosaurs have blunt teeth that look more suited for squid-eating than megapredation," researcher Ryosuke Motani, professor of paleobiology at the University of California, Davis, told UPI in an email. "That is why we thought they were squid eaters." Advertisement But recently, Motani and his research partners discovered the well-preserved remains of a lizard-like aquatic reptile called a thalattosaur inside the stomach of Middle Triassic ichthyosaur. The fossil, described Thursday in the journal iScience, represents the oldest record of megafaunal predation by a marine reptile. "We have to readjust ou...
Paleontologists find new Cambrian predator species with rake-like claws

Paleontologists find new Cambrian predator species with rake-like claws

Science
August 1 (UPI) -- Paleontologists have discovered a new Cambrian predator species hiding among the ancient rocks of Kootenay National Park in the Canadian Rockies. The newly discovered species, now extinct, was one of largest predators on Earth during its heyday 500,000 years ago. With a large, horseshoe crab-like head and a big, curving mouth -- shaped like a pineapple slice, according to researchers -- the species would have been hard to miss. Scientists named the new species Cambroraster falcatus. "The rake-like claws and the large shell-like carapace provide evidence that Cambroraster spent its time hunting for buried prey near the sea floor," Joe Moysiuk, a graduate student based at the Royal Ontario Museum, told UPI. According to Moysiuk, some modern crustaceans, as well as a few ...
Paleontologists diagnose 240-million-year-old proto-turtle with bone cancer

Paleontologists diagnose 240-million-year-old proto-turtle with bone cancer

Science
Feb. 7 (UPI) -- Bone cancer may be nearly as old as bones. Researchers have discovered evidence of an aggressive malignant tumor in the femur of a 240-million-year-old proto-turtle -- the oldest case of bone cancer in amniotes, a lineage of four-limbed vertebrates that includes birds, reptiles and mammals. Scientists described their diagnosis this week in the journal JAMA Oncology. Bone cancer is rare in the fossil record, not because it wasn't around a few hundred million years ago, but because it's hard to spot. Cancerous growths are usually hidden inside bones, only detectable with an X-ray machine or CT scan. The growth on the femur of Pappochelys rosinae -- perhaps the first turtle species -- can be seen with the naked eye. While it was obvious there was something wrong with the pri...