whales
laelaps | April 30, 2010I feel like I have been run over by a truck. Between blogging, working on my book, fieldwork, pitching freelance articles, and research, I just didn't have the energy to come up with something new today. Instead enjoy this post, written a little more than a year ago, about how the hip of a fossil whale was mistaken for the shoulders of an ancient bird. -- Brian
The right hip of Basilosaurus as seen in Lucas' 1900 description.If you were a 19th century paleontologist and you wanted a skeleton of the fossil whale Basilosaurus, there was only one place to look; Alabama. Even though fossils of…
jgoldman | April 24, 2010Earlier this week we talked about how to use whale snot for science.
I especially enjoyed blog bff Scicurious's take on the study:
Budgetary requirement: $5000 for series of expensive remote control helicopters.
Source: Toys R Us.
Justification: Need something that can fly close to a whale and collect snot for measurement. Also, this is the only kind that comes in red, and the gunmetal grey ones suck.
This day, however, we will travel farther, er, south. Through the mouth, down the esophagus, into the stomach, detour through the intestines, take a left at the sphincter, but, what, what's…
laelaps | March 29, 2010
As I mentioned in today's post, dead whales provide food and homes for a variety of marine organisms, and this video (uploaded by Kevin Zelnio of Deep Sea News) shows how whale fall communities change over time. It was produced by the laboratory of Dr. Craig Smith, University of Hawaii.The bone-dwelling worms I wrote about can be seen starting at the one minute mark.
laelaps | March 29, 2010The fail whale comes to rest; the decomposing body of a gray whale is host to a diverse array of scavengers and other deep sea organisms. From Goffredi et al., 2004.
In the deep sea, no carcass goes to waste. Platoons of crabs, fish, and other scavengers make short work of most of the bodies which come to rest on the sea bottom, but every now and then the carrion-eaters are presented with a rotting bonanza; a whale fall. Muscle, viscera, blubber, and bone; it all gets broken down, but it takes so long that the whale carcass actually provides a temporary home for a variety of organisms which…
laelaps | March 18, 2010A 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. They…
laelaps | February 18, 2010An 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 several…
laelaps | January 17, 2010A dolphin skull, photographed at the North Carolina Museum of Natural Sciences.
laelaps | January 16, 2010The skeleton of a blue whale (Balaenoptera musculus), photographed at the North Carolina Museum of Natural Sciences. (Notice the foramina, or small holes, in the upper jaw. In life these housed blood vessels that nourished the whale's baleen plates. They are also useful anatomical clues in determining which fossil whales had baleen.)
laelaps | January 5, 2010A restoration of Mammalodon by Brian Choo (published in Fitzgerald, 2009).
In the introduction to his 1883 lecture on whales, the English anatomist William Henry Flower said;
Few natural groups present so many remarkable, very obvious, and easily appreciated illustrations of several of the most important general laws which appear to have determined the structure of animal bodies, as that selected for my lecture this evening. We shall find the effects of the two opposing forces--that of heredity or conformation to ancestral characters, and that of adaptation to changed environment, whether…
laelaps | December 16, 2009A comparison of the third molars from three species of Pakicetus as viewed from the back. (From Cooper et al., 2009)
Crack open just about any recent popular overview of evolution (namely Why Evolution is True, The Greatest Show on Earth, and Evolution: What the Fossils Say and Why it Matters) and somewhere inside you will find a string of skeletal whales. Starting with either Indohyus or Pakicetus, the illustration will feature a graded series of forms that connect modern whales with their terrestrial ancestors. A caveat may be included in the text to say that we cannot be absolutely sure…
laelaps | October 16, 2009Three restorations (top, left side, and bottom) of the skull of Andrewsiphius. From the Journal of Paleontology paper.
During the past 30 years the evolution of fully aquatic whales from terrestrial ancestors has gone from one of the most enigmatic evolutionary transitions to one of the best documented. Evidence from the fossil record, genetics, and embryology have been combined to document how early whales walked into the sea, but what often has gone unnoticed is the diversity of early whales. In a new paper published in the latest issue of The Journal of Paleontology, cetacean experts J.G.M…
laelaps | September 11, 2009Carl Buell's restoration of Aetiocetus weltoni. From Demere et al., 2008.By now many of you have no doubt seen the abysmally bad story on evolution and creationism in yesterday's Telegraph. After referring to the reactions of fundamentalist Christians to the forthcoming Charles Darwin biopic Creation (based upon the book Annie's Box), the anonymous author of the piece presents the "Top 5" arguments for both evolution and creationism. The choices were baffling; it appeared that rather than do any actual research the writer extracted the selections from a bodily orifice that I will refrain from…
laelaps | July 8, 2009A beautiful artistic reconstruction of Indohyus by Carl Buell.During the last 30 years paleontologists have uncovered a startling amount of fossil evidence which has illuminated the early evolution of whales. The earliest members of the cetacea looked nothing like the marine mammals we are familiar with today, and in December of 2007 a paper in Nature identified a small hoofed mammal called Indohyus as one of the closest relatives to the earliest whales. This hypothesis was supported by a subsequent study published a few months ago in the same journal.
One of the most interesting aspects of…
laelaps | April 24, 2009About four million years ago, in the shallows of an ocean that once covered what is now southern Peru, a large shark bit into the jaw of a baleen whale. The whale had been dead for some time, but it was kept afloat but the gases building up in its body as it decomposed. It was absolutely rotten, but it still presented a free meal to the scavenging shark. As the shark bit down, however, one of its teeth became stuck in the whale's jaw bone and broke off. No matter. The lost tooth would soon be replaced by another.
The above scenario does involve a bit of speculation, but such events certainly…
laelaps | March 29, 2009The skull of Dorudon, photographed at the National Museum of Natural History.
laelaps | March 24, 2009Last week I wrote about the shuffling and reshuffling of relationships between whales, hippos, pigs, and an extinct group of mammals called raoellids. One aspect of the paper I did not comment on, however, was the problematic placement of the enormous predator Andrewsarchus.
In November of 1924 Henry Fairfield Osborn described the huge skull of a predatory mammal discovered during a American Museum of Natural History expedition to Mongolia. Unfortunately there was little other than the skull left of the great beast, but Osborn thought it belonged to a gigantic omnivore. Osborn named it…
laelaps | March 21, 2009Maiacetus.I am having a lot of fun visiting the various museums and landmarks in Washington, D.C. this weekend, and while I don't have much time for blogging I wanted to share a photo from my brief stop at the National Museum of Natural History. Even though I spent most of the day talking to paleobiologists behind the scenes (watch Dinosaur Tracking for details) I did have the chance to briefly check out the new ocean gallery. Pictured above is the skull of the suspended mount of Maiacetus on display in that exhibit.
laelaps | March 19, 2009The big news in this week's issue of Nature was the discovery of a small ornithischian dinosaur covered in bristles, but there was another, shorter paper that caught my eye. In December 2007 Nature printed a short communication on Indohyus, a small artiodactyl that seemed like a good candidate for the type of creature that whales evolved from. Paleontologists Hans Thewissen and Lisa Noelle Cooper explain the significance of Indohyus to whale evolution in this video;
There was something that bothered me about the systematic analysis of Indohyus, however. In the paper's phylogenetic tree…
laelaps | February 3, 2009The extinct whale Dorudon, from the new PLoS One paper.When the English anatomist William H. Flower proposed that whales had evolved from terrestrial ungulates in 1883 he cast doubt upon the notion that the direct ancestors of early whales chiefly used their limbs for swimming. If they did, Flower reasoned, whales would not have evolved their distinctive method of aquatic locomotion, typified by vertical oscillations of their fluked tails. Instead Flower suggested that the stock that gave rise to whales would have had broad, flat tails that paved the way for cetacean locomotion as we know it…
laelaps | February 2, 2009The right hip of Basilosaurus as seen in Lucas' 1900 description.If you were a 19th century American paleontologist and you wanted a Basilosaurus skeleton there was only one place to look; Alabama. Even though fossils of the ancient whale had been found elsewhere their bones were most abundant in Alabama, and S.B. Buckley, Albert Koch, and others exhumed multiple specimens of the extinct whale from the southern state. Unfortunately, however, most of the skeletons were fragmentary. Even though long chains of vertebrae were often found intact other parts of the skeleton, most notably the head…