fossils
pharyngula | April 1, 2009
A fish is a fish, right? They're just a blur of aquatic beasties that most people distinguish by flavor, rather than morphology or descent. But fish are incredibly diverse, far more diverse than terrestrial vertebrates, and there are significant divisions within the group. Most people know of one big distinction, between the Chondrichthyes (fish with cartilaginous skeletons, like sharks and rays) and the Osteichthyes (fish with bony skeletons), but there's another particularly interesting split within the Osteichthyes: the distinction between Sarcopterygians (the word means "fleshy fins",…
pharyngula | March 20, 2009I'm not going to say much about this since Ed Yong has an excellent write-up, but a new feathered dinosaur has been discovered, called Tianyulong. As you can see in this image of the fossil, it was bristling with a fuzz of thin fibers — proto-feathers.
(Click for larger image)a, Main slab of the holotype (STMN 26-3). b, Broken slab. The scale bar in b refers also to a. c, Close-up of skull and mandible. d, Interpretive drawing of skull and mandible. e, Close-up of dentition. Abbreviations: a, angular; aof, antorbital fossa; ca, caudal vertebrae; cv, cervical vertebrae; d, dentary; dv, dorsal…
pharyngula | March 18, 2009
Several new and spectacular cephalopod fossils from 95 million years ago have been found in Lebanon. "Spectacular" is not hyperbole — these specimens have wonderfully well-preserved soft parts, mineralized in fine-grained calcium phosphate, and you can see…well, take a look.
(Click for larger image)Keuppia levante sp. nov. from the Upper Cenomanian (Metoicoceras geslinianum Zone) of Hâdjoula (Lebanon). A,
holotype, MSNM i26320a. B, sketch of the holotype.
The arms (all eight of them) are intact, right down to the suckers; muscles and gills are preserved; the animal has an ink sac; there is a…
pharyngula | March 6, 2009If you ever wanted to peer deeply into the decayed and shriveled eyes of Otzi, the 5,000 year old iceman, now you can. High resolution images of Otzi are available on the web, and you can pan and zoom all over his body. You can also find 3D images, and special closeups of his tattoos.
pharyngula | March 6, 2009
That question has an answer: they crouched like birds. A 198 million year old fossil trackway from Utah has preserved a print of a theropod dinosaur taking a break, resting with hands curled inward and knuckle down, and legs bent. Except for the forelimbs, of course, it's very birdlike.
Restoration of Early Jurassic environment preserved at the SGDS, with the theropod Dilophosaurus wetherilli in bird-like resting pose, demonstrating the manufacture of SGDS.18.T1 resting trace.
Here's the section of the trace fossil they used to reconstruct the animal's posture.
A, Overhead, slightly oblique…
pharyngula | February 27, 2009
Isn't that beautiful? It's an ancient footprint in some lumpy rocks in Kenya…but it is 1½ million years old. It comes from the Koobi Fora formation, familiar to anyone who follows human evolution, and is probably from Homo ergaster. There aren't a lot of them; one series of three hominin trails containing 2-7 prints, and a stratigraphically separate section with one trail of 2 prints and an isolated single print. But there they are, a preserved record of a trivial event — a few of our remote relatives taking a walk across a mudflat by a river — rendered awesome by their rarity and the…
pharyngula | February 26, 2009
The media is getting another science story wrong. I keep seeing this discovery of an array of fossil placoderms as revealing the origins of sex, and that's not right. Sex is much, much older, and arose in single-celled organisms. Come on, plants reproduce sexually. A fish is so far removed from the time of origin of sexual reproduction that it can't tell us much about its origins.
Let's get it right. These fossils tells us about the origin of fu…uh, errm, mating in vertebrates.
What we have are a set of placoderm fossils from the Devonian (380 million years ago) of Western Australia (The…
gregladen | February 15, 2009"The Giants' Shoulders" is a monthly science blogging event, in which authors are invited to submit posts on "classic" scientific papers. Information about the carnival can be found here.
The last Giants' was hosted at The Questionable Authority, here. The next issue will be hosted at The Evilutionary Biologist: All Science, All The Time, which resided here.
Since this is Darwin Month in Darwin Year and almost, indeed, Darwin Day, we start with ... Paleontology. We'll get to Darwin at the end.
Early palaentologists and the Giant killer lungfish from Hell as well as the Revenge of…
gregladen | February 12, 2009In 1833, Darwin spent a fair amount of time on the East Coast of South America, including in the Pampas, where he had access to abundant fossil material. Here I'd like to examine his writings about some of the megafauna, including Toxodon, Mastodon, and horses, and his further considerations of biogeography and evolution.
reposted
In the vicinity of Rio Tercero...
Hearing ... of the remains of one of the old giants, which a man told me he had seen on the banks of the Parana, I procured a canoe, and proceeded to the place. Two groups of immense bones projected in bold relief from the…
pharyngula | February 10, 2009
Fans of the great Cambrian predator, Anomalocaris, will be pleased to hear that a cousin lived at least until the Devonian, over 100 million years later. That makes this a fairly successful clade of great-appendage arthropods — a group characterized by a pair of very large and often spiky manipulatory/feeding arms located in front of the mouth. Here's the new fellow, Schinderhannes bartelsi:
(click for larger image)Holotype of Schinderhannes bartelsi. (A) Ventral. (B) Interpretative drawing of ventral side. l, left; r, right; A1, great appendage; A2, flaplike appendage; sp, spine; fm, flap…
gregladen | February 10, 2009Charles Darwin wrote a book called Geological Observations on South America. Since Fitzroy needed to carry out intensive and extensive coastal mapping in South America, and Darwin was, at heart, a geologist more than anything else (at least during the Beagle's voyage), this meant that Darwin would become the world's expert on South American geology. Much of The Voyage is about his expeditions and observations. Part of this, of course, was figuring out the paleontology of the region.
reposted with minor revisions
Bahia Blanca is a port at the northern end of Patagonia. Chapter V of The…
pharyngula | February 5, 2009
Just wait — this one will be featured in some cheesy Sci-Fi channel creature feature in a few months. Paleontologists have dug up a fossil boa that lived 58-60 million years ago. They haven't found a complete skeleton, but there's enough to get an estimate of the size. Look at these vertebrae!
a, Type specimen (UF/IGM 1) in anterior view compared to scale with a precloacal vertebra from approximately 65% along the precloacal column of a 3.4 m Boa constrictor. Type specimen (UF/IGM 1) shown in posterior view (b), left lateral view (c) and dorsal view (d). Seven articulated precloacal…
pharyngula | February 4, 2009My teaching schedule this semester is a major time-suck; I'm teaching genetics and all of its associated labs (you really don't want to know how much prep time goes into setting up fly labs), I'm doing some major revision of the content this year, and I've got this asymmetric schedule that packs everything into the first half of each week. So I simply have to protest when those evil (Stein was right!) scientists announce a major discovery on a Tuesday, which just happens to be the very worst day of the week for me. They've gone and found another important whale transitional fossil, Maiacetus…
edyong | February 3, 2009Nine years ago, a team of fossil-hunters led by Philip Gingerich from the University of Michigan uncovered something amazing - the petrified remains of an ancient whale, but one unlike any that had been found before. Within the creature's abdomen lay a collection of similar but much smaller bones. They were the fossilised remains of a foetal whale, perfectly preserved within the belly of its mother. Gingerich says, "This is the 'Lucy' of whale evolution."
The creatures are new to science and Gingerich have called them Maiacetus inuus. The genus name is an amalgamation of the Greek words "…
pharyngula | January 26, 2009Lucy's skeleton is on tour, and is currently on display at the Pacific Science Center — a lovely and interesting place even when the most famous australopithecine in the world isn't holding court. Here's the surprising news: Pacific northwesterners are not flocking to the museum. The science center is losing big buckets of money on the exhibit, and other museums around the country are hesitating about booking it — it may close after its Seattle run, and I won't get to see it!
I can't believe this. You have a once-in-a-lifetime opportunity to see a wonderful relic of our ancient history, and…
pharyngula | January 4, 2009
Spiders are amazingly sophisticated animals, and probably the premiere complex adaptation of modern spiders is the ability to spin silk. They have multiple internal glands that can produce multiple kinds of silk — webs contain different kinds, from structural strands to adhesive strands, and other kinds are used for spinning egg cases and for wrapping prey — and they are sprayed out through small spigots mounted on swiveling spinnerets, which are modified opisthosomal (abdominal) limbs. Obviously, these detailed features did not spontaneously appear all at once, but had to have evolved…
grrlscientist | December 19, 2008tags: evolution, behavioral ecology, parental care, egg incubation, dinosaurs, birds
The Oviraptorid dinosaur, Citipati osmolskae,
on a nest of eggs that was unearthed in the Gobi desert
of Mongolia by the American Museum of Natural History.
Image: Mick Ellison, American Museum of Natural History.
Oviraptors ("egg seizer") were given their name because their fossil remains were first discovered on top of a pile of eggs. Because of their close proximity to clutches of dinosaur eggs, it was initially assumed that these dinosaurs were eating them. However, in his 1924 paper, their…
grrlscientist | December 18, 2008tags: Austroraptor cabazai, dinosaurs, Dromaeosauridae, birds, fossils, taxonomy, evolution
The newly unveiled Austroraptor cabazai (left) attacks a juvenile sauropod dinosaur in an artist's interpretation.
The giant raptor, found in Argentina, measured between 16.5 and 21 feet (5 to 6.5 meters) long, making it one of the largest raptors to roam Earth 70 million years ago, a new study finds.
A dramatic new carnivorous dinosaur that was bigger than a car was unveiled yesterday in public at the Museo Argentino de Ciencias Naturales (the Argentine, or Bernardino Rivadavia, Museum of Natural…
pharyngula | November 26, 2008
Now this is an interesting beast. It's a 220 million year old fossil from China of an animal that is distinctly turtle-like. Here's a look at its dorsal side:
a, Skeleton in dorsal view. b, Skull in dorsal view. c, Skull in ventral view. d, Body in dorsal view. Teeth on the upper jaw and palatal elements were scratched out during excavation. Abbreviations: ar, articular; as, astragalus; ca, calcaneum; d, dentary; dep, dorsal process of epiplastron; dsc, dorsal process of scapula; ep, epiplastron; fe, femur; fi, fibula; gpep, gular projection of epiplastron; hu, humerus; hyo, hyoplastron; hyp…
grrlscientist | November 16, 2008tags: triceratops, dinosaur exhibit, Boston Natural History Museum, Triceratops Cliff, streaming video
This fascinating streaming video shows a time-lapse creation of a triceratops exhibit, Triceratops Cliff, in the Boston Natural History Museum. This video is especially relevant for Sunday morning because, besides being really interesting, this video will answer the question once and for all: Does god have a butt crack? [1:47].