Herodotus Returns


Fossil footprints lengthen history of land vertebrates
January 8, 2010, 8:23 am
Filed under: Fossils | Tags: , ,

Newly discovered footprints lengthen the history of land vertebrates by at least 18 million years.

The discovery of fossil footprints from early backboned land animals in Poland leads to the sensational conclusion that our ancestors left the water at least 18 million years earlier than previously thought.

“These results force us to reconsider our whole picture of the transition from fish to land animals,” says Per Ahlberg of Uppsala University, one of the two leaders of the study.

For nearly eighty years, palaeontologists have been scouring the planet for fossil bones and skeletons of the earliest land vertebrates or “tetrapods” — the ultimate progenitors of all later amphibians, reptiles, birds and mammals including ourselves. Their discoveries have suggested that the first tetrapods evolved relatively rapidly from lobe-finned fishes, through a short-lived intermediate stage represented by “elpistostegids” such as Tiktaalik, about 380 million years ago. But there is another potential source of information about the earliest tetrapods: the fossilized footprints they left behind.

In the new study a Polish-Swedish team describe a rich and securely dated footprint locality from Zachelmie Quarry in Poland that pushes back the origin of tetrapods a full 18 million years beyond the earliest skeletal evidence and forces a dramatic reassessment of the transition from water to land.

Advertisements


Ancient whale was a dwarf mud-sucker
January 4, 2010, 1:06 am
Filed under: Fossils | Tags: , ,

Twenty-five-million-year-old fossils excavated in Australia show a primitive whale who captured his prey by slurping up mouthfuls of mud.

An ancient dwarf whale unearthed in southeastern Australia captured its prey by slurping up mouthfuls of mud, a new study says.

The fossil whale, thought to be between 25 and 28 million years old, hints that mud sucking might have been a precursor to the filter feeding used by today’s baleen whales.

Many modern whale species use hair-like structures called baleen to filter tiny prey such as krill from seawater. Baleen species include the humpback, the minke, and the largest animal ever to have lived on Earth, the blue whale.

The newfound fossil whale, which measures just nine feet (three meters) long, shares the same distinct jaw and skull structures as today’s baleens.

But the tiny whale also had teeth, said study author Erich Fitzgerald, a paleontologist at Museum Victoria in Melbourne, Australia

More on mud-slurping whales.



Top Ten Dinosaur and Fossil Finds of 2009
December 31, 2009, 1:48 am
Filed under: Fossils | Tags: , ,

National Geographic’s top ten dinosaur and fossil finds of 2009 includes a snake longer than a bus, the skeleton of the oldest human ancestor, and Ida, the 47 million-year-old skeleton that may be ‘missing link’ between humans and lemurs.

10. Biggest Trilobite Sea Beasts Found … in SwarmsThe “remarkable,” yard-long, horseshoe crab-like arthropods roamed in swarms of up to a thousand animals, a May study suggests.
9. “Lost World” of Dinosaurs Survived Mass Extinction?An isolated group of dinosaurs may have outlived their doomed relatives by as much as half a million years, an April study suggested.
8. A Third of Dinosaur Species Never Existed?

Young dinosaurs weren’t Mini-Me versions of their parents, evidence presented in October suggests—meaning that up to a third of dinosaur species may be misidentified.

7. Tiny “T. Rex” Found —150-Pound Species Came FirstNo heavier than a small man, Raptorex was Mini-Me to T. rex’s dinosaur Dr. Evil. But in this case, the tiny gave rise to the titanic, researchers said in September. 
6. Five “Oddball” Crocs Discovered, Including Dinosaur-Eater

A “saber-toothed cat in armor” and a pancake-shaped predator are among five strange, dinosaur-era crocodile cousins discovered in the Sahara, archaeologists announced in November. Meet BoarCroc, PancakeCroc, DuckCroc, RatCroc, and DogCroc.

5. AUSTRALIA DINOSAUR PICTURES: 3 New Species Found

Fossils of a ferocious predator and two giant plant-eaters, named for an Aussie poet and his creations, have been unearthed in the outback, paleontologists announced in July.

4. NEW FOSSIL PHOTOS: “Graceful Weasel,” Jewel Bug, More

A long-legged mammal, a sharp-toothed rodent, and an iridescent beetle are among the more than 6,500 Eocene-epoch fossils unearthed in Germany’s Messel Pit, scientists announced in August.


3. Biggest Snake Discovered; Was Longer Than a Bus

The 60-million-year-old reptile was also heavier than a car, scientists said in February, adding that the fossil could shed light on climate change. 

2. Oldest Skeleton of Human Ancestor Found

There was never a chimp-like missing link between humans and today’s apes, according to an October fossil-skeleton study that could rewrite human evolutionary history. Said one scientist, “It changes everything.” 

1. “Missing Link” Found: Fossil Connects Humans, Lemurs?

The 47-million-year-old, exceptionally preserved primate fossil “Ida,” unveiled on May 20, was hailed by some as a major discovery in human evolution. The publicity frenzy made National Geographic News’s brief coverage our most viewed page of the year—and inspired a backlash as some experts, including one here at Nat Geo HQ, suggested Ida was more media event than milestone.