Fossils

There have been numerous discoveries of various tracks made by long-extinct species and ancestors of living ones. You can even buy casts of numerous tracks from PaleoScene.

A cool new set of tracks has made news this week, and it appears to show how a pterosaur made its landing. Not Exactly Rocket Science blogger Ed Yong has the scoop:

Several million years ago, at a time when dinosaurs walked the earth, a flying reptile - a pterosaur - came in for a landing. As it approached, it used its powerful wings to slow itself down and hit the ground feet first. It took a short hopping step before landing a second time. On solid ground, it leant forward, put its arms down and walked away on all fours....

The first set of footprints has no corresponding handprints, the heel portion isn't isn't deeper or longer than usual, and there aren't any piles of sediment around them. The pterosaur clearly landed feet-first, but it did so gently rather than braking heavily into the ground. Nonetheless, it wasn't a perfect landing. The slight impressions left by its claws and the short distance before the next set of footprints suggest that the animal stuttered slightly, hopping forward before coming in to land.

For more info on Dinosaur tracks and Ichnology (the study of fossil tracks and other non-skeletal fossils such as eggs), check out this excellent introduction from Glen J. Kuban.

A new study describes hominid fossils found in Spain in 2004 as having unusual features known to be largely similar only to other genus Homo species (photo credit).

In a study appearing in the Proceedings of the National Academy of Sciences, Salvador Moyà-Solà, director of the Institut Català de Paleontologia (ICP) at the Universitat Autònoma de Barcelona, and colleagues present evidence for the new genus and species, dubbed Anoiapithecus brevirostris. The scientific name is derived from the region where the fossil was found (l’Anoia) and also from its "modern" facial morphology, characterized by a very short face. (...)

Anoiapithecus displays a very modern facial morphology, with a muzzle prognathism (i.e., protrusion of the jaw) so reduced that, within the family Hominidae, scientists can only find comparable values within the genus Homo, whereas the remaining great apes are notoriously more prognathic (i.e., having jaws that project forward markedly). The extraordinary resemblance does not indicate that Anoiapithecus has any relationship with Homo, the researchers note. However, the similarity might be a case of evolutionary convergence, where two species evolving separately share common features.

Lluc's discovery may also hold an important clue to the geographical origin of the hominid family. Some scientists have suspected that a group of primitive hominoids known as kenyapithecines (recorded from the Middle Miocene of Africa and Eurasia) might have been the ancestral group that all hominids came from. The detailed morphological study of the cranial remains of Lluc showed that, together with the modern anatomical features of hominids (e.g., nasal aperture wide at the base, high zygomatic rood, deep palate), it displays a set of primitive features, such as thick dental enamel, teeth with globulous cusps, very robust mandible and very procumbent premaxilla. These features characterize a group of primitive hominoids from the African Middle Miocene, known as afropithecids.

"This is the most complete primate fossil before human burial," said Dr. Jorn Hurum of the Natural History Museum at the University of Oslo, who led the study of the fossil, that of a young female primate.

"And it's not a few million years old; it's 47 million years old," Hurum said, speaking at a news conference at the American Museum of Natural History in New York. (...)

Ida is at "the very root of anthropoid evolution -- when primates were first developing the features that would evolve into our own," said a news release from the Natural History Museum at the University of Oslo.

It has, among other things, opposable thumbs, similar to humans' and unlike those found on other modern mammals. It has fingernails instead of claws. And by examining the structure of its hind legs (one of which is partly missing), scientists say they can see evidence of evolutionary changes that would eventually lead to primates standing upright.