The asteroid collision widely thought to have killed the dinosaurs also led to extreme devastation among snake and lizard species, according to new research — including the extinction of a newly identified lizard Yale and Harvard scientists have named Obamadon gracilis.
“The asteroid event is typically thought of as affecting the dinosaurs primarily,” said Nicholas R. Longrich, a postdoctoral associate with Yale’s Department of Geology and Geophysics and lead author of the study. “But it basically cut this broad swath across the entire ecosystem, taking out everything. Snakes and lizards were hit extremely hard.” (more…)
Answer may be ‘adaptive zones’ that limit species number, life scientists report
There are more than 400,000 species of beetles and only two species of the tuatara, a reptile cousin of snakes and lizards that lives in New Zealand. Crocodiles and alligators, while nearly 250 million years old, have diversified into only 23 species. Why evolution has produced “winners” — including mammals and many species of birds and fish — and “losers” is a major question in evolutionary biology.
Scientists have often posited that because some animal and plant lineages are much older than others, they have had more time to produce new species (the dearth of crocodiles notwithstanding). This idea — that time is an important predictor of species number — underlies many theoretical models used by biologists. However, it fails to explain species numbers across all multi-cellular life on the planet, a team of life scientists reports Aug. 28 in the online journal PLoS Biology, a publication of the Public Library of Science. (more…)
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…)
ANN ARBOR, Mich.— Nature teems with examples of evolutionary arms races between predators and prey, with the predator species gradually evolving a new mode of attack for each defensive adaptation that arises in the prey species.
These adaptations are often portrayed as reciprocal, with prey and predator acting as two sides in an endless evolutionary tug of war known as co-evolution. (more…)
HONOLULU – A species of lizard is now extinct from the Hawaiian Islands, making it the latest native vertebrate species to become extirpated from this tropical archipelago.
The copper striped blue-tailed skink (Emoia impar) — a sleek lizard with smooth, polished scales and a long, sky-blue tail — was last confirmed in the Na’Pali coast of Kauai in the 1960s. But repeated field surveys on Kauai, Oahu, Maui and Hawai’i islands from 1988 to 2008 have yielded no sightings or specimens. (more…)
