paleontology
laelaps | March 25, 2010
I'll be the first to admit it; the specimen was not much to look at. Seventy years after being dug out of the ground much of it had crumbled into four-foot-long Y, and the curved teeth that once stood upright in that jaw had slumped out of their sockets into the sulfur-smelling debris. All the same, it was an impressive sight.
During the past four years I have spent much of my free time reading about evolution and paleontology. Popular summaries, symposium volumes, technical papers; the numerous books that clutter my office and the disorganized mess of PDFs on my hard drive have taught me…
laelaps | March 24, 2010
Megarachne, (changed to Mesothelae for broadcast) restored as an enormous spider in the series Before the Dinosaurs: Walking With Monsters.
Imagine that you are are standing in a massive junkyard with the remains of cars strewn all about you. A few are relatively complete, but most of the heap is made up of bits and pieces of models from the entire history of automotive innovation. If you were to reach down and pick up one of the scraps, would you be able to tell the make and model of the car it came from?
The challenges a paleontologist faces in reconstructing the life of the past are…
laelaps | March 23, 2010
A comparison of three-dimensional scans of hominin footprints. Top) A footprint made by an experimental subject using a normal, "extended" gait. Middle) A footprint made by an experimental subject using a "bent-knee, bent-hip" gait. Bottom) A Laetoli footprints. From Raichlen et al., 2010.
About 3.6 million years ago, at a spot now in Laetoli, Tanzania, a pair of hominins trudged through the ashfall dumped onto the landscape by a nearby volcano. We don't know for certain what they looked like (it is generally believed that they were Australopithecus afarensis from the presence of fossils…
laelaps | March 22, 2010
The skull of Mosasaurus maximus, photographed at the New Jersey State Museum.
laelaps | March 21, 2010
The mount of a musk ox (Ovibos moschatus), photographed at the New Jersey State Museum.
laelaps | March 19, 2010
The skeleton of an elk-moose (Cervalces scotti), photographed at the New Jersey State Museum.
laelaps | March 18, 2010
A photograph and line drawing (left side) of the fossil dolphin Astadelphis gastaldii. The crescent-shaped line in the line drawing represents the bite of a large shark, with the red portions representing damage done directly to the bone. From Bianucci et al, 2010.
Shark attacks are events of speed and violence. When they have locked on to a prey item sharks seem to come out of nowhere, and though they can be quite gentle with their jaws (as on occasions when they are unsure about whether something is food or not) their ranks of serrated teeth can inflict a devastating amount of damage.…
laelaps | March 17, 2010
Earlier this week I discussed how to find a publisher for your book and how blogs can be useful tools in that process, but what about the effort that goes into completing a manuscript?
As Michael has pointed out in his latest blog-length contribution to our conversation, every writer is different. How Michael approached writing Sand was very different from how I went about composing Written in Stone, so rather than try to lay out a precise set of writing rules I will attempt to summarize my unique writing experience.
By the time I signed with Bellevue Literary Press in the autumn of 2009…
laelaps | March 13, 2010I love the work that Larry Witmer and his students do at Ohio University. Not only is it cutting-edge anatomical research that helps us better understand prehistoric organisms, but the Witmer lab is constantly sharing parts of their work via the web. They even have their own YouTube feed with lots of 3D renderings of fossil animals, including one of my favorite prehistoric mammals, Archaeotherium. The video below presents a view of its skull and brain cast, as well as a quick look at its jaws in action:
laelaps | March 12, 2010
When it comes to aliens, Hollywood really does not have much imagination. Most extraterrestrials that have appeared on the big screen look very much like us, or are at least some kind of four-to-six-limbed vertebrate, and this says more about out own vanity than anything else. It would be far more interesting, I think, to take the weird and wonderful organisms of the Cambrian as inspiration for alien life forms, and two new critters have just been added to the odd Cambrian menagerie.
A restoration of Herpetogaster collinsi by Marianne Collins. From Caron et al, 2010.
What was three…
laelaps | March 10, 2010
A muskox (Ovibos moschatus), photographed in Alaska. From Flickr user drurydrama.
Of all the mass extinctions that have occurred during earth's history, among the most hotly debated is the one which wiped out mammoths, saber-toothed cats, giant ground sloths, and the other peculiar members of the Pleistocene megafauna around 12,000 years ago. It was not the most severe mass extinction, not by a long shot, but unlike the end-Cretaceous catastrophe 65 million years ago there is no single "smoking gun" that can account for the pattern of extinction. Instead the Pleistocene mass extinction…
grrlscientist | March 10, 2010tags: evolution, evolutionary biology, ancient DNA, aDNA, molecular biology, molecular ecology, archaeology, paleontology, fossil eggshell, extinct birds, giant moa, Dinornis robustus, elephant birds, Aepyornis maximus, Mullerornis, Thunderbirds, Genyornis, researchblogging.org,peer-reviewed research, peer-reviewed paper, journal club
Elephant bird, Aepyornis maximus, egg
compared to a human hand with a hummingbird egg balanced on a fingertip.
To conduct my avian research, I've isolated and sequenced DNA from a variety of specimens, such as blood, muscle, skin and a variety of internal…
laelaps | March 9, 2010
A simplified evolutionary tree of primate relationships showing the placement of Darwinius in relationship to other groups. From Williams et al., 2010.
The study of human origins can be a paradoxical thing. We know that we evolved from ancestral apes (and, in fact, are just one peculiar kind of ape), yet we are obsessed with the features that distinguish us from our close relatives. The "big questions" in evolutionary anthropology, from why we stand upright to how our brains became so large, are all centered around distancing us from a prehistoric ape baseline. Despite our preoccupation…
laelaps | March 3, 2010
The exceptionally preserved skeleton of Darwinius, known popularly as "Ida." From PLoS One.
Almost ten months ago an international team of researchers introduced the world to an exquisitely-preserved primate from the 47 million year old oil shales of Messel, Germany. Dubbed Darwinius masillae, and nicknamed "Ida" and "The Link", the fossil was touted as one of our earliest primate ancestors in a massive media campaign worthy of a Hollywood blockbuster. Yet the trouble was that there was no solid evidence that Darwinius was one of our ancestors. Despite the marketing blitz promoting the…
laelaps | March 1, 2010
An adult chimpanzee in Bossou, Guinea uses hammer and anvil stones to crack nuts as younger individuals look on. From Haslam et al., 2009.
Before 1859 the idea that humans lived alongside the mammoths, ground sloths, and saber-toothed cats of the not-too-distant past was almost heretical. Not only was there no irrefutable evidence that our species stretched so far back in time, but the very notion that we could have survived alongside such imposing Pleistocene mammals strained credulity. Contrary to what might be immediately expected, however, it was not Darwin's famous abstract On the…
laelaps | February 24, 2010
A Cuban crocodile (Crocodylus rhombifer), photographed at the National Zoo in Washington, DC.
No one knew what happened to William Olson. At about three in the afternoon on April 13, 1966 he had been swimming with his friends from the Peace Corps in the part of the Baro river that ran through Gambela, Ethiopia when he suddenly disappeared. The last person to remember seeing him was hunter Karl Luthy. One moment Olson was standing in the river, pressing his body against the current, and the next he was gone.
Luthy could not be sure, but he was almost certain that Olson had been taken by a…
laelaps | February 23, 2010
A reconstruction of a dead Edmontosaurus on display at the Museum of Ancient Life at Thanksgiving Point, Utah.
laelaps | February 22, 2010
A restoration of the giant, durophagous shark Ptychodus, courtesy paleo-artist Matt Celeskey.
The study of prehistoric sharks is no easy task. Specialists in other branches of vertebrate paleontology at least have the reasonable hope of discovering complete skeletons of their subjects; except in instances of exceptional preservation the scientists who study sharks typically only have teeth and a few vertebrae to work with. Still, you can tell a lot about a shark by its teeth, and a new study published in Cretaceous Research suggests that one peculiar form was a shell-crushing giant.…
laelaps | February 18, 2010
An engraving of Koch's "Hydrarchos", from the American Phrenological Journal. (Pardon the smudges)
In July of 1845 the amateur fossil hunter Albert Koch brought his sea monster to New York City. A cousin of the serpentine creatures that so many had claimed to see off the coast of New England, the 114-foot-long skeleton looked to be the bones of the Leviathan itself, and crowds flocked to see the its ghastly form. It was called "Hydrarchos" by Koch, and it was was the ruler of the ancient seas.
It was also a monstrous hoax. The Hydrarchos skeleton did not belong to any one animal but to…
laelaps | February 17, 2010
Detail of a Charles R. Knight mural depicting a family a mastodons.
Fossils often turn up in unexpected places. As people have dug swimming pools, tilled farms, blasted through mountains, and quarried the land for minerals traces of ancient life sometimes come to the surface, from isolated shark teeth to skeletons of our extinct hominin relatives. Even fossil graveyards are found this way every now and then, like the one found in a southern Pennsylvania quarry a little more than a century ago.
In late April 1907 William Jacob Holland, a paleontologist and director of Pittsburgh's Carnegie…