Tag Archives: fossil

Some Mammals Used Highly Complex Teeth to Compete With Dinosaurs

By Guest PostMarch 19, 2012Nature, Science3 d images, alistair evans, angiosperms, australia, back teeth, bumps, computed tomography, ct, cusps, dinosaur extinction, dinosaurs, event, extinction, finland, food, fossil, gregory p wilson, ian corfe, insect pollinators, jukka jernvall, mammal, mesozoic era, mikael fortelius, monash university, mountain range, multituberculates, Nature, paleontologist, peter smits, rodent, scanning, tooth surface, topography, tubercles, university of helsinki, university of washington, vince stricherz

Conventional wisdom holds that during the Mesozoic Era, mammals were small creatures that held on at life’s edges. But at least one mammal group, rodent-like creatures called multituberculates, actually flourished during the last 20 million years of the dinosaurs’ reign and survived their extinction 66 million years ago.

New research led by a University of Washington paleontologist suggests that the multituberculates did so well in part because they developed numerous tubercles (bumps, or cusps) on their back teeth that allowed them to feed largely on angiosperms, flowering plants that were just becoming commonplace. (more…)

Iridescent, Feathered Dinosaur Offers Fresh Evidence That Feathers Evolved to Attract Mates

By Guest PostMarch 9, 2012Scienceaerodynamic functions, anchiornis, archaeopteryx, austin, catapults, color, dinosaurs, evolution of feathers, feather pattern, feathers, fossil, four winged dinosaur, julia clarke, living birds, mark norell, mate attracting, matt shawkey, mick ellison, microraptor, modern birds, peking university, pigment, quanguo li, rui pei, thermoregulation, university of akron, university of texas, velociraptor

AUSTIN, Texas — A team of American and Chinese researchers has revealed the detailed feather pattern and color of Microraptor, a pigeon-sized, four-winged dinosaur that lived about 120 million years ago. A new specimen shows the dinosaur had a glossy iridescent sheen and that its tail was narrow and adorned with a pair of streamer feathers, suggesting the importance of display in the early evolution of feathers, as presented in the March 9 edition of the journal Science.

The research was conducted by scientists at the Beijing Museum of Natural History, Peking University, The University of Texas at Austin, the University of Akron, and the American Museum of Natural History. (more…)

Evolution of Earliest Horses Driven by Climate Change

By Guest PostFebruary 24, 2012Environment, Nature, Scienceaaron wood, atmosphere, bighorn basin, body size, cabin fork area, carbon, carbon dioxide, cause and effect, climate model, clydesdale, concentration, doug boyer, dwarfing phenomenon, earliest horse, evolution, florida museum of natural history, fossil, geochemical analysis, global temperature, h richard lane, horse teeth, industrial revolution, jonathan bloch, mammal, national science foundation, natural selection, North America, nsf, ocean, ornithologist, oxygen levels, paleocene-eocene thermal maximum, petm, prediction, ross secord, sifrhippus sandae, stephen chester, temperature, university of florida, university of nebraska lincoln, worland, yale

*The hotter it gets, the smaller the animal?*

When Sifrhippus sandae, the earliest known horse, first appeared in the forests of North America more than 50 million years ago, it would not have been mistaken for a Clydesdale.

It weighed in at around 12 pounds–and it was destined to get much smaller over the ensuing millennia.

Sifrhippus lived during the Paleocene-Eocene Thermal Maximum (PETM), a 175,000-year interval of time some 56 million years ago in which average global temperatures rose by about 10 degrees Fahrenheit. (more…)

Global Extinction: Gradual Doom as Bad as Abrupt

By Guest PostFebruary 8, 2012Environment, Sciencebrooks ellwood, canadian arctic, carbon dioxide, charles henderson, coal deposit, dead zone, earth, ellesmere island, extinction, factor, fossil, geologic history, geology, global extinction, greenhouse, greenhouse gas, h richard lane, harry rowe, indian ocean, katherine freeman, marine life, mass extinction, national science foundation, ocean, permian period, permian triassic boundary, sedimentary rock, siberian traps, siberian volcanic activity, south china, steven bates, tethys, the great dying, thomas algeo, timothy lyons, united states, university of calgary, university of cincinnati, volcanic deposit, volcanic rock, volcanism in siberia, warming, west blind fiord

*In “The Great Dying” 250 million years ago, the end came slowly*

The deadliest mass extinction of all took a long time to kill 90 percent of Earth’s marine life–and it killed in stages–according to a newly published report.

It shows that mass extinctions need not be sudden events.

Thomas Algeo, a geologist at the University of Cincinnati, and 13 colleagues have produced a high-resolution look at the geology of a Permian-Triassic boundary section on Ellesmere Island in the Canadian Arctic. (more…)

Ancient Meat-Loving Predators Survived for 35-Million Years

By Guest PostDecember 9, 2011Scienceagile predators, ancient predator, beaufort group, cape breton university, dental, extinction, fossil, hypercarnivores, komodo dragon, lizards, mammals, middle permian, pristerognathus assemblage zone, robert reisz, saw like teeth, sean modesto, skeletal design, South Africa, species, terrestrial fauna, university of toronto mississauga, varanopid pelycosaur, varanopids

Lived through period of species extinction

A species of ancient predator with saw-like teeth, sleek bodies and a voracious appetite for meat survived a major extinction at a time when the distant relatives of mammals ruled the earth.

A detailed description of a fossil that scientists identify as a varanopid “pelycosaur” is published in the December issue of Naturwissenschaften – The Science of Nature. Professors Sean Modesto from Cape Breton University, a U of T alumnus, and Robert Reisz from University of Toronto Mississauga provide evidence that a group of ancient, agile predators called varanopids survived for more than 35 million years and co-existed with more advanced animals. (more…)

Fossil Discovery Represents New Milestone in Early Mammal Evolution

By Guest PostAugust 26, 2011Nature, Scienceancestors of mammals, carnegie mammalogist, carnegie museum of natural history, China, chong xi yuan, chuck lydeard, dna based methods of dating evolution, earliest known fossil of eutherians, eomaia, eutherian mammals, evolutionary hypotheses, fossil, fossil record, genetic data, john wible, juramaia sinensis, jurassic, jurassic mother from china, kangaroos, mammal evolution, marsupials, metatherians, molecular clock, monotremes, national science foundation, northeast china fossil, nsf, paleontologist, placental mammals, platypus, qiang ji, qing jin meng, shrew like mammal, zhe xi luo

*Northeast China fossil provides new information about earliest ancestors of today’s mammals*

A well-preserved fossil discovered in northeast China provides new information about the earliest ancestors of most of today’s mammal species–the placental mammals. (more…)

Evolution of Human ‘Super-Brain’ Tied To Development of Bipedalism, Tool-Making

By Guest PostApril 22, 2011Scienceafrica, ants, archaeological evidence, archaeologist, Arctic, bees, bipedalism, don river, Europe, evolution of human mind, fossil, france, Germany, honeybees, human ancestors, human brain, human mind, john hoffecker, kostenk, lucy, modern mind, moscow, russia, social insects, stone tools, super brain, university of colorado boulder, waggle dance

Scientists seeking to understand the origin of the human mind may want to look to honeybees — not ancestral apes — for at least some of the answers, according to a University of Colorado Boulder archaeologist.

CU-Boulder Research Associate John Hoffecker said there is abundant fossil and archaeological evidence for the evolution of the human mind, including its unique power to create a potentially infinite variety of thoughts expressed in the form of sentences, art and technologies. He attributes the evolving power of the mind to the formation of what he calls the “super-brain,” or collective mind, an event that took place in Africa no later than 75,000 years ago. (more…)

What Did T. Rex Eat? Each Other.

By Guest PostOctober 20, 2010Sciencecanada, cannibalism, carnivore, dinosaurs, fossil, gregory erickson, john horner, largest terrestrial carnivores, majungatholus, mammal tooth, marks, museum, nick longrich, North America, paleontologists, philip currie, scavengers, t rex, tyrannosaurus rex, united states, yale researcher

T. rex was the only big carnivore in western North America 65 million years ago that was capable of making such large gouges. Image credit: Nicholas Longrich

It turns out that the undisputed king of the dinosaurs, Tyrannosaurus rex, didn’t just eat other dinosaurs but also each other. Paleontologists from the United States and Canada have found bite marks on the giants’ bones that were made by other T. rex, according to a new study published online Oct. 15 in the journal PLoS ONE.

While searching through dinosaur fossil collections for another study on dinosaur bones with mammal tooth marks, Yale researcher Nick Longrich discovered a bone with especially large gouges in them. Given the age and location of the fossil, the marks had to be made by T. rex, Longrich said. “They’re the kind of marks that any big carnivore could have made, but T. rex was the only big carnivore in western North America 65 million years ago.” (more…)