mammals
laelaps | June 25, 2009
Richard Owen's restoration of Glyptodon. From Brinkman (2009).
Perhaps one of the primary reasons that there is so much to say about Charles Darwin is that he left us so much material to scrutinize. Outside of his famous printed works there are numerous notebooks and a staggering amount of personal correspondence which are constantly being parsed for insights into how he formulated his evolutionary ideas. Indeed, there is still scholarly debate about when Darwin embraced the idea of evolution and what observations spurred him to that intellectual turning point, and a new paper by Paul…
laelaps | June 24, 2009
Mother gorilla (Gorilla gorilla) Mandara holding her child Kibibi. Photographed at the National Zoo.
laelaps | June 23, 2009If you can handle some more hype about human evolution, here's a snippet from the (more or less) recent BBC documentary "The Ape That Took Over the World." It is about the controversial placement of Kenyanthropus in hominid evolution;
I do not have time to do a full write-up here (especially since I have not as yet seen the show in full), but the evolutionary placement of Kenyanthropus is more controversial than this clip admits. Kenyanthropus appears to be a hominin, but whether it represents a new genus, an already-known form of Australopithecus, or something else is still being debated…
laelaps | June 22, 2009Fossil teeth can be tricky things. In 1922 paleontologist H.F. Osborn believed that he had found the first evidence of an extinct fossil ape from North America on the basis of a worn molar from Nebraska, but it later turned out to be the tooth of a prehistoric peccary. Four years later, by contrast, Davidson Black named a new species of ancient human on the basis of a handful of teeth recovered from Dragon Bone Hill in China. These turned out to belong to Homo erectus. Both paleontologists made bold steps on the basis of sparingly little evidence, but with entirely different outcomes.
Last…
laelaps | June 22, 2009
Rokan the Sumatran tiger (Panthera tigris sumatrae), photographed at the National Zoo.
laelaps | June 21, 2009
A calf and its mother (Bos primigenius taurus), photographed in suburban New Jersey.
laelaps | June 20, 2009
Two Amur tigers (Panthera tigris altaica), photographed at the Philadelphia Zoo.
laelaps | June 17, 2009
California sea lions (Zalophus californianus) and their trainers, photographed at the Central Park Zoo.
laelaps | June 15, 2009
The skull of a spotted hyena (Crocuta crocuta), photographed at the AMNH's "Extreme Mammals" exhibit.
[Author's note: This post gets a little bit graphic, so those who are made squeamish by taphonomy might want to skip this one.]
There was something funny about the assemblage of Homo erectus fossils found at Dragon Bone Hill in Zhoukoudian, China. There were plenty of teeth and skulls but scarcely any post-cranial remains. Where were the bodies?
The majority of Homo erectus fossils from Zhoukoudian were discovered and studied by an international team of scientists during the 1920's and…
laelaps | June 14, 2009
The skull of the Taung child (Australopithecus africanus); the fragmentary remains of Orrorin; the scattered bones of Homo erectus from Dragon Bone Hill; a skullcap of a young Paranthropus from Swartkrans, South Africa. What do all these hominin fossils have in common? They all bear the tell-tale marks of predators, from birds of prey to gigantic hyenas, and run distinctly against the notion that humans have always dominated the landscape. There have always been toothy shadows that stalked the night during our history, and the significance of this fact is the focus of Donna Hart and Robert…
laelaps | June 11, 2009
The exceptionally preserved skeleton of Darwinius, known popularly as "Ida." From PLoS One.
Even though it has been about a month since Darwinius (or "Ida", if you like) hit the public scene there is still plenty to talk about. From uncertain evolutionary relationships to the interaction between scientists and the media, this controversy has given us plenty to discuss. One of the most worrying aspects of this entire ordeal, however, has been the prospect that media companies influenced the scientific study of Ida.
As Earle Holland wrote on the Ohio State University On Research... blog, the…
laelaps | June 10, 2009
A red fox (Vulpes vulpes), photographed at Prime Hook National Wildlife Refuge, Delaware
laelaps | June 9, 2009
A restoration of the skull of Thylacoleo. From The Ancient Life History of the Earth.
Without a doubt, the extinct marsupial predator Thylacoleo was one of the strangest carnivorous mammals ever to have evolved. This predator from ancient Australia did not have piercing canines but instead bit into prey with large, forward facing incisors, and it sheared flesh from its kills with huge, cleaver-like premolars. Even though it evolved from herbivorous ancestors, we now know that Thylacoleo was most certainly a carnivore.
The preferred diet of Thylacoleo has not always been so clear-cut,…