Life

Paleontology

Northern Extinction: Alaskan horses shrank, then disappeared

Horses that lived in Alaska shrank dramatically in body size before they went extinct at the end of the last ice age.

Plants

Micro Sculptors

Snippets of RNA that control biochemical reactions by squelching the creation of specific proteins play a role in the development of leaves.

Animals

Not-So-Great Hunter: Said the spider to the fly—Eek! I’m outta here

The poisonous brown recluse spider may turn out not to be a fearsome hunter so much as a scavenger.

Animals

First Impressions: Early view biases spider’s mate choice

In a new wrinkle on how females develop their tastes in males, a test has found that young female wolf spiders that see a male's courtship display grow up with a preference for that look in mates.

Paleontology

Ancient atmosphere was productive

New laboratory experiments suggest that extra carbon dioxide in the atmosphere in the era just before the dinosaurs went extinct may have boosted plant productivity to at least three times that found in today’s ecosystems.

Paleontology

Healed scars tag T. rex as predator

Healed wounds on the fossil skull of a Triceratops—wounds that match the size and shape of those that would be made by Tyrannosaurus rex—are a strong sign that the tooth scrapes are a result of attempted predation, not scavenging.

Paleontology

Role of gastroliths in digestion questioned

New analyses of the gastroliths in ostriches are casting doubt on the theory that large, plant-eating dinosaurs swallowed stones to grind up tough vegetation and thereby aid their digestion.

Paleontology

Tracks suggest chase, capture, and after-meal respite

A 1.3-meter-long, S-shaped trail of fossil footprints discovered in southwestern Indiana includes one set of disappearing tracks—suggesting an ancient chase—and an impression where the predator rested after its meal.

Paleontology

Bob, Bob, Bobbin’ Along: Dinosaur buoyancy may explain odd tracks

New lab experiments and computer analyses may explain how some of the heftiest four-legged dinosaurs ever to walk on Earth could have left trackways that include the imprints of only their front feet.

Paleontology

Fossils of Flyers: Bones tell why Atlantic albatross disappeared

Ancient albatross fossils suggest that rising sea levels 400,000 years ago wiped out the North Atlantic population of short-tailed albatross.

Animals

Your Spiral or Mine? Snail gene reverses coil, makes new species

A snail with a shell spiraling to the right can't mate readily with a lefty, so changes in the single gene that controls shell direction have created new snail species.

Paleontology

Reptile remains fill in fossil record

The fossil remains of a sphenodontian, an ancient, lizardlike reptile, are helping fill a 120-million-year-old gap between this creature's ancestors and today's tuatara, sole survivors of the once prominent group.