fossils
pharyngula | March 16, 2007
The latest Nature reveals a new primitive mammal fossil collected in the Mesozoic strata of the Yan mountains of China. It's small and unprepossessing, but it has at least two noteworthy novelties, and first among them is that it represents another step in the transition from the reptilian to the mammalian jaw and ear.
Here's the beautiful little beast; as you can see, it's very small, and we need to look very closely at some details of its morphology to see what's special about it.
(click for larger image)Main part of the holotype (Nanjing University-Paleontology NJU-P06001A). b, Skeletal…
pharyngula | March 2, 2007(click for larger image)Reconstruction of O. reburrus by M. Collins. The precise arrangement of the anteriormost region remains somewhat conjectural.
Halkieriids are Cambrian animals that looked like slugs in scale mail; often when they died their scales, called sclerites, dissociated and scattered, and their sclerites represent a significant component of the small shelly fauna of the early Cambrian. They typically had their front and back ends capped with shells that resembled those we see in bivalve brachiopods. Wiwaxiids were also sluglike, but sported very prominent, long sclerites, and…
grrlscientist | February 7, 2007Two skeletons from the Neolithic period locked in a tender embrace were found by Archaeologists buried outside Mantua, only 25 miles south of Verona, the romantic city where Shakespeare set the star-crossed tale of "Romeo and Juliet." The burial site was recently located during construction work for a factory building in the outskirts of Mantua. Alongside the couple, archaeologists found flint tools, including arrowheads and a knife, said Elena Menotti, the archaeologist who led the dig.
One hypothesis being examined is that the man was killed and the woman then sacrificed so that his soul…
pharyngula | January 30, 2007Zimmer describes some of the more recent work on Flores Man — people are still arguing over whether the fossil is of a peculiarly abnormal human with microcephaly, or whether there was a species of 'miniaturized' Homo living on the islands of the Pacific. Trying to establish common characteristics of microcephalics is an interesting project, but it doesn't answer the question. We need more fossils! Among the good news Carl mentions is the report that more excavations will be underway this year.
grrlscientist | January 24, 2007
Titanis Walleri, Terror bird.
artist's rendering.
Image: University of Florida.
University of Florida paleontologist Bruce MacFadden said his team has determined that a prehistoric 7 foot tall flightless "terror bird," Titanis walleri, arrived in North America from South America long before a land bridge connected the two continents. The bird apparently island hopped to North America on islands that make up the mountains that now form mountains on the isthmus of Panama.
"It was previously thought that Titanis immigrated to Texas across the Panamanian land bridge that formed about 3 million…
grrlscientist | January 24, 2007A paleontological treasure trove of fossils was discovered recently in a cave in the Nullarbor Plain in southern Australia. This discovery includes mammals, birds, reptiles and a marsupial lion, Thylacoleo carnifex (pictured), and 23 species of kangaroo, including eight of which are new to science. These fossils date back to between 400,000-800,000 years ago.
The creatures apparently fell to their deaths through openings in the dusty surface of the plain that periodically opened and closed over millennia.
"Sitting in the darkness next to this skeleton, you really got the sense of the animal…
grrlscientist | January 23, 2007tags: Microraptor gui, microraptor, biplane, bird flight, evolution
The ancestors of modern birds are thought to have been small, feathered, dinosaurs, the theropods. One of these small feathered dinosaurs is Microraptor gui, a feathered dromaosaur that lived 125 million years ago in what is now China. According to the evidence, Microraptor gui was one of the earliest gliders. But unlike modern birds, it appears to have utilized four wings, like a biplane, because it had long and asymmetric flight feathers on both its hands and feet.
According to initial interpretations, Microraptor flew…
pharyngula | January 23, 2007I reported a while back that there was a possibility that the phosphatized pre-Cambrian Doushantuo specimens might not be embryos—they might be a particular class of bacteria—but there may be evidence against that hypothesis. John Lynch finds a description of more advanced embryos, intermediate stages that would link at least some of the blastulae described so far to unambiguous multicellular organisms.
pharyngula | January 14, 2007Any other fans of the Phasmatodea out there? For years, we kept a collection of stick insects — they are extremely easy to raise, and although they aren't exactly dynamos of activity, they're weird enough to be entertaining — and so I perk up when I notice a paper on them. The latest news is the discovery of a fossil leaf insect (also a member of the Phasmatodea, but a smaller subgroup specialized to resemble leaves rather than twigs) from 47 million years ago that resembles modern forms very closely. The cryptic camouflage of this group is ancient, and probably coevolved with the emergence…
grrlscientist | December 30, 2006
Turritella perattenuata fossil, next to a nickel (for scale).
Caloosahatchee fm[1]., Brandtley quarry, near Highway 31, Florida.
This is a Caloosahatchee fossil, the remarkably elongate and now-extinct Turritella perattenuata. The Caloosahatchee is said to straddle the Plio-Pleistocene boundary, which, according to the Geological Society of America Geological Time Scale, occurs at 1.8 Myr. The Caloosahatchee fauna is tropical, but the Lower Pleistocene Bermont formation above it in the South Florida section shows temperate elements.
Image: Biosparite.
I am receiving so many gorgeous…
pharyngula | December 23, 2006Almost ten years ago, there was a spectacular fossil discovery in China: microfossils, tiny organisms preserved by phosphatization, that revealed amazing levels of fine detail. These specimens were identified as early animal embryos on the basis of a number of properties.
The cells were dimpled and shaped by adjoining cells, suggesting a flexible membrane—not a cell wall. This rules out algae, fungi, and plants.
The number of cells within each specimen was usually a power of 2. This is something we typically see in cleaving embryos, the sequence from 1 to 2 to 4 to 8 to 16 cells.
They were…
pharyngula | December 21, 2006Oh, man, I feel for the kids nowadays. When I was an itty-bitty dinosaur-happy tyke, it seemed like there was a manageable amount of Latin nomenclature you had to memorize to keep up with the dinosaur clan. Now it's like there's a new one added every week, and you've got to be a freakin' genius to be able to follow them all. Kids do still go wacky over dinosaurs, right? We haven't gone so far down the tubes that the little nerds are neglecting their paleontology, have we?
Anyway, there's a new one out of Spain, Turiasaurus riodevensis, an old school sauropod, and it's a big one. Pictures…
pharyngula | December 13, 2006This sad jumble of bones is all that remains of Volaticotherium antiquus, a small rat-sized mammal that was recently dug up in China. There are two particularly outstanding things about this creature.
One is that browner layer in the rock: that isn't an artifact, it's a bit of soft tissue that was preserved, called a patagium. A patagium is a thin membrane stretched between the limbs, and is used for…flying! This animal probably lived much like a modern flying squirrel (although it is definitely not a squirrel), gliding from tree to tree.
The second surprise is the age. This is a Mesozoic…
grrlscientist | December 6, 2006
These Lower Pleistocene shells date to around 1-1.6 Myr ( Bermont formation). I collected them on a Florida Paleontological Society field trip nearly two years ago. If you were a Florida-Gulf-Coast sheller, you would recognize many of the shells as having modern representatives despite their age. There has been essentially a "freeze" on molluscan evolution in the Atlantic shell fauna since the inception of the 20 or so ice ages that have occurred in the Pleistocene. You said you were not averse to having fossils shells, so take a look. Notice the cone snails (Conus) in the strew. Nature ran…
grrlscientist | December 3, 2006
Darwin's Evolution of Man.
.
Richard Leakey, the famous paleoanthropologist, is battling with powerful evangelical church leaders in Kenya. These fundamentalist wingnuts are pressuring Kenya's national museum to hide its world-famous collection of hominid fossils that detail the evolution of humans' early ancestors.
Leakey stated that the wingnuts' statements are "the most outrageous comments I have ever heard."
"The National Museums of Kenya should be extremely strong in presenting a very forceful case for the evolutionary theory of the origins of mankind,"continued Leakey. "The…
grrlscientist | November 24, 2006tags: Cinerocaris magnifica, Nymphatelina gravida, ostracod, arthropoda, crustacean, fossil, zoology, biology
Recently, geologists made a stunning discovery: hard boiled eggs that are over 425 million years old! The scientists, who are from the USA and the UK, discovered a female from a new ostracod species, Nymphatelina gravida -- a minute relative of the shrimp -- complete with a brood of approximately 20 eggs and 2 possible juveniles inside her body. Other parts of her soft anatomy were also preserved, including legs and eyes.
"Ostracods are common, pin-head sized crustaceans known from…
pharyngula | November 24, 2006You know how we great clumsy gallumphing unsophisticated atheists are always comparing belief in gods to belief in fairies at the bottom of the garden or tooth fairies or whatever? We may have to revise those arguments.
Now we really have to worry. If some space probe snaps a picture of an orbiting teapot, we'll have nothin'.
Crap. Sean knocks the props out from under my godlessness. Now I'm going to have to convert to something…what does everyone recommend? Catholicism, LDS, Scientology, etc., or should I just go all the way primitive, erect a phallus-shaped rock in my backyard, and start…
pharyngula | November 21, 2006
I've been reading Valentine's On the Origin of Phyla(amzn/b&n/abe/pwll) lately, and I have to tell you, it's a hard slog. This is one of those extremely information-dense science texts that rather gracelessly hammers you with the data and difficult concepts on page after page. I am convinced that James W. Valentine is ten times smarter than I am and knows ten thousand times as much, and it's a struggle to squeeze that volume of knowledge into my miniscule brain pan.
One thing I would like to greatly condense and simplify is his discussion of the Cambrian 'explosion'. Misinterpretation of…
pharyngula | November 13, 2006
Oh happy day, the Sea Urchin Genome Project has reached fruition with the publication of the full sequence in last week's issue of Science. This news has been all over the web, I know, so I'm late in getting my two cents in, but hey, I had a busy weekend, and and I had to spend a fair amount of time actually reading the papers. They didn't just publish one mega-paper, but they had a whole section on Strongylocentrotus purpuratus, with a genomics mega-paper and articles on ecology and paleogenomics and the immune system and the transcriptome, and even a big poster of highlights of sea urchin…
pharyngula | October 29, 2006Reconstruction of Priscomyzon in dorsal (top) and left lateral (bottom) views. b, Macropthalmia stage of Lampetra showing anterior location of orbit and smaller oral disc, both positioned in front of the branchial region. The total length of the specimen is 116 mm. Drawings in a and b are scaled to show equivalent head lengths: from anterior limit of the oral disc to rear of the branchial region. Horizontal bars indicate the anterior–posterior span of the oral disc in each species.
The life of a parasite must be a good one, and often successful; the creature at the top of the drawing above is…