Fossil Finds

[rogue06]

Researchers have announced the discovery of oldest known dinosaur nesting site, dating to 190 myo (Early Jurassic), which has been excavated in Golden Gate Highlands National Park, located in Free State, Republic of South Africa, near the Lesotho border.

The site, which predates other known dinosaur nesting grounds by 100 million years, includes at least 10 nests, something like 340 eggs (some of which contain fossilized embryos in several different stages of development), footprints, hatchlings and the remains of adults for this species, the bipedal prosauropod dinosaur Massospondylus, which grew to be 4-6 meters (13-19¾') long.

The nests themselves were uncovered in at least three distinct layers of rock within the excavation, each indicating a different point in time. The nests were probably fairly shallow since all of the eggs within one are in the same layer.

The researchers were unable to determine whether the nests were covered by vegetation or if they were buried because of the nature of the sediments preclude the preservation of plant fossil remains. It is entirely possible that the mother guarded the nests.

From the fine-grained nature of the sediments containing the eggs, the researchers think the nests were likely built near a lake or a slow-moving river. Such sites often have a good deal of vegetation which would be perfect for a group of herbivores.

As for the eggs, which are round, they are between 6-7cm (2⅓-2¾") in diameter. One of the eggs actually reveals that the head of the unborn dinosaur was pushed out of the egg after death. The researchers think gases produced by decay caused this to happen.

Considering the large size of the mothers and the small size of the eggs and the fact that the eggs seemed to be organized into tightly clustered groups suggests that the mothers may have arranged their eggs carefully after laying them. The large number of small eggs in each nest indicate this was likely a survival strategy that allowed at least a few to survive.

The site also had multiple hatchling foot and handprints indicating that the young dinosaurs remained at the nesting site long enough to have grown at least twice in size. This confirms evidence provided late last year at a Protoceratops nesting site in Mongolia that at least some newborn dinosaurs hung around the nest they were hatched in.

The layout of the nests indicates that Massospondylus returned repeatedly to this site (a behavior called "nesting fidelity") and, because the multiple nests were found within the same layers, laid eggs together as a group ("colonial nesting"). This is the earliest evidence of such behavior known in the fossil record.

As the lead author, Robert Reisz, a professor of biology at the University of Toronto at Mississauga, noted all of "the eggs, embryos and nests come from the rocks of a nearly vertical road cut only 25 meters (82') long" which indicates that there are a probably a lot more in the cliff, still covered by tons of rock and awaiting discovery after they're exposed by natural weathering.

I'm still awaiting a copy of the paper (Oldest known dinosaurian nesting site and reproductive biology of the Early Jurassic sauropodmorph Massospondylus) or at least an abstract, which was published in the journal Proceedings of the National Academy of Sciences (PNAS), and will link to it when it becomes available.

Attachment 72328 Attachment 72329

Further Reading:

Ancient dinosaur nursery -- the oldest nesting site ever found

Oldest Dinosaur 'Nursery' Discovered

Tiny footprints found amid ancient dinosaur nests

Oldest dinosaur nesting site ever found contains hundreds of 190-million-year-old eggs

190 million-year-old dinosaur nesting site found

Ancient dinosaur nursery oldest nesting site yet found

Oldest dinosaur nursery found in South Africa

Oldest dinosaur nest unearthed

Dinosaurs were caring mothers, new discovery finds

Oldest dinosaur nests unearthed

UPDATE:
Confusion at the PNAS website delayed the release, but here is the Abstract: Oldest known dinosaurian nesting site and reproductive biology of the Early Jurassic sauropodomorph Massospondylus

[rogue06]

After using a powerful scanning electron microscope to examine a preserved wing feather from Archaeopteryx that had been found in a German limestone quarry near the town of Solnhofen back in 1861 and comparing it to 115 feathers from 87 species of living birds, researchers have been able to conclude that it had been jet black in color.

The examination revealed hundreds of the melanosomes encased in patches in the feather that are roughly 1 millionth of a meter long and 250 billionths of a meter wide — that equates to about one-hundredth the diameter of a human hair in length and less than a wavelength of visible light in width!

The black feather color might have assisted Archaeopteryx with regulating its temperature, acted as camouflage, and/or been utilized for display.

Further, the sausage-shaped melanosomes that supplied the black pigment within the creature's feather would have given the feathers additional structural support and are evidence that the wing feathers were rigid and durable just like those on today's birds.

IOW, the melanosomes found in Archaeopteryx's feather would have provided similar structural advantages as those seen in feathers of modern birds, regardless of whether the pigmentation originally evolved for another purpose.

As the researcher's team leader Ryan Carney, an evolutionary biologist at Brown University in Providence, Rhode Island, noted, in modern bird feathers, "these melanosomes provide additional strength and resistance to abrasion from flight."

"If Archaeopteryx was flapping or gliding, the presence of these cells would have given the feathers additional structural support," Carney said. "This would have been advantageous during this early evolutionary stage of dinosaur flight."

And black feathers actually appear to provide a flight advantage in that they contain more melanosomes than do feathers of other colors, and the melanosomes can bind with keratin proteins in the feathers to make them thicker, stronger, as well as more durable.

While rigid wing feathers could have helped Archaeopteryx flap and glide, whether Archaeopteryx could actually take off under its own power is still unknown and the subject of debate.

Being that Archaeopteryx's feather structure is identical to that of living birds this means that wing feathers likely evolved as early as 150 mya during the Jurassic.

ArchaeopteryxFeather.jpg

Further Reading:

Winged dinosaur Archaeopteryx dressed for flight includes short video

Feathered Dinosaur Had Black Wings?

WAS FIRST WINGED DINOSAUR JET BLACK?

Black adorned feathers of winged dinosaurs

First birds 'had black feathers'

On the wing: Famous fossil had black feathers

Winged Jurassic dinosaur was black, like a raven - and had feathery wings just like today's birds

[rogue06]

In a tiny piece of amber only 5mm (0.19") long x 4mm (0.15") wide x 4mm (0.15") deep excavated from the La Búcara mine, located in the Cordillera Septentrional mountain range, which runs parallel to the north coast of the Dominican Republic, a one of a kind fossil has been discovered.

Contained within the minuscule piece of amber is an ectoparasite of bats known as a bat fly. These are external vampiric parasites of bats that only inhabit the fur and wing membranes of bats where they feed on its blood. This particular specimen is from an extinct genus that probably lived between 20 and 30 mya (Mid Tertiary).

Bat flies, or more properly Streblidae, tend to be flattish with long legs and are now found in bats all over the world. Today there are at least 237 species divided among approximately 33 genera and 5 subfamilies. They're host-specific, with different species only found on specific species of bat, although sometimes with multiple species of flies sharing a host bat.

The reason this discovery is remarkable is that, besides not preserving well, bat flies only leave their hosts to mate making the odds of ever finding one almost beyond calculating.

The researchers officially named this bat fly Vetufebrus ovatus, with the first part a combination of the Latin words "vestus" and "febris" meaning old and fever respectively. The specific epithet is from the Latin "ovatus" for ovate, referring to the shape of the oocysts of the fossil bat fly.

As indicated by the name this bat fly was carrying a disease, specifically a type of malaria.

The discovery marks the first fossil ever found of a bat fly and indicates that they've been around for at least half as long as bats themselves which date back to 50 mya. Possibly longer in that this amber has proved difficult to date and could possibly be as old as 45 million years.

It also means that they were spreading bat malaria in the New World for this long as well. Presently, only nycteribiid flies have been identified as transmitters for bat malaria, but this discovery indicates that streblids may also be spreading the disease.

As George O. Poinar, a professor with Oregon State University's Department of Zoology, wrote in one of two studies published on the find, "While no malaria parasites have been found in extant streblids, they probably occur and it is possible that streblids were the earliest lineage of flies that transmitted bat malaria to Chiroptera [bats]."

Poinar's findings were made in two separate papers published by two different professional journals, Systematic Parasitology and Parasites and Vectors.

batfly.jpg

Further Reading:

Vetufebrus ovatus n. gen., n. sp. (Haemospororida: Plasmodiidae) vectored by a streblid bat fly (Diptera: Streblidae) in Dominican amber Abstract & Paper*

A Battle of the Vampires, 20 Million Years Ago?

First 'Vampire' Bat Fly Fossil Discovered



* Sorry, I don't have a link to the one in Systematic Parasitology

[rogue06]

Further Reading:

Vetufebrus ovatus n. gen., n. sp. (Haemospororida: Plasmodiidae) vectored by a streblid bat fly (Diptera: Streblidae) in Dominican amber Abstract & Paper*

A Battle of the Vampires, 20 Million Years Ago?

First 'Vampire' Bat Fly Fossil Discovered



* Sorry, I don't have a link to the one in Systematic Parasitology

I believe this is the abstract from Systematic Parasitology: The first fossil streblid bat fly, Enischnomyia stegosoma n. g., n. sp. (Diptera: Hippoboscoidea: Streblidae)

[rogue06]

Several hundred fossilized footprints probably made by at least four different types of dinosaurs back between 140 to 150 mya (Late Jurassic) were found in the Guihuamu National Geological Park (a site known for its large number of petrified ancient woods) in Yanqing county, a subdivision or suburb of Beijing, China.

The prints are, according to Zhang Jianping a professor at China University of Geosciences in Beijing, the first dinosaur fossils ever discovered in the city and were laid down by theropods, ornithopods, thyreophora and likely some sauropods as well.

Most of the prints are found at one location where the researchers counted several hundred footprints as well as seven to eight lines formed by consecutive steps.

dinotracksbeijijg.jpg

Further Reading:

Dinosaur footprints discovered in Beijing


Dinosaur Footprints Confirmed in Beijing 1 min video after ad

[rogue06]

Researchers have announced the discovery of primitive sponge-like fossils they say represent the earliest record of metazoan life on the planet, living roughly 760 mya -- which is over 200 million years before the start of the Cambrian and the so-called "Cambrian Explosion"

Over a thousand of the tiny fossils, which range in size from 0.3mm (0.01") to 5mm (0.19") in the longest dimension, were excavated from the black limestone from the Otavi and Nama Groups in Namibia, principally in Etosha National Park in the Kunene Region of the northwestern portion of the country.

The calcareous sponges are elongate ovoid to globular in shape and, although individuals vary, the overall form of each remains similar (described as "vase-shaped") and are perforated and pierced by numerous miniscule holes. They were examined under electron microscopy (SEM), electron probe imaging (BSE), cathode luminescence microscopy (CL) and X-ray microtomography (XMT).

The sponge was named Otavia antiqua by the researchers after the Otavi Group in which most of the fossils were found in with the second part being due to their age.

The discovery confirms models crafted by geneticists using "molecular clocks" and biomarkers which had suggested sponges existed well before the "Cambrian Explosion" as well as Reitner and Wörheide's research in 2002 that found spicules with demosponge affinities in some fossils from Nevada dated at 750 myo that had been considered unsubstantiated.

As one of the researchers, Dr. Anthony R. Prave, of the Department of Earth Sciences at the University of St Andrews in Scotland, stated that, "The aspect of this that's rather satisfying, at least intellectually, is that it is in broad agreement with what geneticists would tell us based on looking at molecular clocks when we should see the first advent of large multi-cellular life forms."

Otavia would have lived in the earliest oceans, during a time when there was considerably less oxygen in the atmosphere than today and, according to Prave, would have lived in quiet water settings, like in lagoons.

The researchers think Otavia probably fed on algae and bacteria by drawing water through the microscopic holes that cover its exterior and excreting what is left over would be pushed out of those same small holes.



Further Reading:

The first animals: ca. 760-million-year-old sponge-like fossils from Namibia Abstract & Paper

The oldest animal fossils

Oldest animal ever found in Namibia?

Fossil find could be world's first animals

Namibia fossils, Otavia antiqua, are "world's first animals," scientists say

[rogue06]

Researchers have succeeded at re-creating the love song of a long-extinct primitive bush cricket, whose modern descendants are also known as katydids, from 165 mya (Mid Jurassic), based on an analysis of an exceptionally well-preserved and detailed fossil discovered in Inner Mongolia's Jiulongshan Formation.

The fossil was in such excellent condition that with the help of a microscope the researchers were able to clearly see the stridulating organs on the wing (a row of teeth on one wing against a plectrum on the other) that the cricket rubbed together to create their mating music.

As one of the authors of the paper describing this find, Daniel Robert of the University of Bristol's School of Biological Sciences, observed, "Even the undersides of the wings were perfectly preserved, because the silt the fossils were found in was so fine, so we could see the ridges of teeth."

Elaborating further Robert added that, "The file, or ridges, on one wing is so complete that if you measure the distance between the teeth, they'll tell you the type of song they sang." He said that "they would've made a resonant sound - a bit like a violin."

The early bush cricket is of a previously unknown species and was named by the researchers Archaboilus musicus because the music-making structures in its body were so clearly visible.

While alive the creature would have possessed relatively large wings, measuring slightly over 70mm (2¾") long with broad stripes of color. Its closest living relatives include katydids (Tettigonidae) and grigs (Prophalangopsidae).

In order to predict the frequency of the tone Archaboilus produced the researchers compared its song apparatus to those of 59 modern-day katydid species and the frequency of sound they made. They found that shorter files tend to create a lower-frequency sound.

Next, they fed all those readings and the characteristics of the insects' songs into a mathematical model the accuracy of which was verified by being used to accurately predict the songs known to be sung by two living katydid species thought to be most closely related to the extinct cricket.

Afterwards, it was merely a matter of seeing where A. musicus would fit in that model and estimating the frequency of its song. Their conclusion, based on the size of the wing and the precise spacing of the teeth, was that this Jurassic katydid would have produced a continuous "chirp" at a single, steady frequency of 6.4kHz lasting 16 milliseconds.

Such a single-note tone should have transmitted efficiently -- a regular wave of sound well-suited for communicating over long distances and close to the ground as well as penetrating a noisy environment cluttered with vegetation thereby allowing any female cricket in the vicinity to detect a male's song above the rabble created by other creatures.

As one of the other authors, Fernando Montealegre-Zapata, a biologist also with the University of Bristol's School of Biological Sciences, pointed out, “Using a low-pitched song, A musicus was acoustically adapted to long-distance communication in a lightly cluttered environment, such as a Jurassic forest."

“This Jurassic bushcricket thus sheds light on the potential auditory capacity of other animals, and helps us learn a little more about the ambiance of a world long gone. It also suggests the evolutionary mechanisms that drove modern bushcrickets to develop ultrasonic signals for sexual pairing and for avoiding an increasingly relevant echolocating predator, but that only happened 100 million years later, possibly with the appearance of bats.”

These findings indicate that since the ancestors of today's katydids were well-adapted for music-making 165 mya that they might have begun chirping at least 50 million years earlier, during the Triassic Period, thanks to, as Montealegre-Zapata puts it, "the formation of random teeth across several veins on the forewings, and the associated production of noisy sounds."

It also shows that the earliest bushcrickets were among the first animals to produce loud sounds by rubbing different parts of their bodies together. While this behavior is most commonly observed in insects, some fish, lobsters, snakes, and spiders also do it.

Jurassiccricketwingstructure.jpg
The comb-like musical instrument in the cricket's wing

Further Reading:

Wing stridulation in a Jurassic katydid (Insecta, Orthoptera) produced low-pitched musical calls to attract females Abstract

Fossil cricket: Jurassic love song reconstructed

Jurassic cricket's song recreated

Fossil cricket reveals Jurassic love song

Hear the call of a Jurassic katydid

The sweet song of a Jurassic cricket

Prehistoric cricket love songs recreated for your listening pleasure

Hear it for yourself

[Teluog]

Rogue, do you know what academic journals publish on matters regarding evidence for evolution? After becoming aware of the wide world of biblical scholarship by talking to the Christians here and through Tektonics, and after many essays at Bible College, I see just how much info there is regarding all kinds of matters on the Bible and have seen numerous academic journals and articles dedicated to the study of it. But what is there for evolution? The main reason I'm asking is not just in case I want to research into it but also to see if there is in fact a huge basis full of data for evolution that Christians are massively ignorant of.

[wattsr1]

Rogue, do you know what academic journals publish on matters regarding evidence for evolution? After becoming aware of the wide world of biblical scholarship by talking to the Christians here and through Tektonics, and after many essays at Bible College, I see just how much info there is regarding all kinds of matters on the Bible and have seen numerous academic journals and articles dedicated to the study of it. But what is there for evolution? The main reason I'm asking is not just in case I want to research into it but also to see if there is in fact a huge basis full of data for evolution that Christians are massively ignorant of.

I'll add my bit before Rougue06 replies, ITOK.

Like the atomic theory of matter, evidence for evolution is pretty well settled as far as mainstream research goes, and this includes many Christians.

Hence, research these days deals with working out the nuts and bolts of evolution, including its mechanism(s). And there is a huge body of research literature on that. Many of the researchers involved would be Christian themselves.

Here is a great ariticle summarising evidence for evolution (It's long and packed full of information):-

http://www.talkorigins.org/faqs/comdesc/

Here is an online journal which has lots of research articles on evolution:-

http://www.plosone.org/static/browse.action

Search for the word "evolution" in the title at the above link and you will find 800 results. This is for one journal, using just one word "evolution".

The beauty of PLoS 1 is that the articles are online for you to see just what is out there. On top of this, you get "Evolution", "Nature", "Science", "PNAS", "The Journal of Molecular Biology", etc, and etc, and etc. Unfortunately, these journals have a pay-wall to most of their articles.

Then there are the books:-

Donald Prothero: "Evoluton: What the fossils say and why it matters"
Jennifer Clack: "Gaining Ground"
Jerry A Coyne: "Why Evolution is True"
Sean Carroll: "Endless Forms Most Beautiful".
Dawkins: He's a great writer on evolution, although you might have to put up with some of his anti-theistic arguments.
Ken Miller: Finding Darwin's God
Francis Collins: The Language of God

The latter two (at least) are Christians and both accept evolution.


You will find that a great many Christians do actually accept evolution.

So it's not as if evolution is accepted by a few of we shady atheists who manage to do a smidgin of work that might get published. It's a vibrant field of science, contributed to by both Christians and non Christians. And their work is published in all those journals I mentioned above, plus a lot more.

[Tiggy]

Rogue, do you know what academic journals publish on matters regarding evidence for evolution? After becoming aware of the wide world of biblical scholarship by talking to the Christians here and through Tektonics, and after many essays at Bible College, I see just how much info there is regarding all kinds of matters on the Bible and have seen numerous academic journals and articles dedicated to the study of it. But what is there for evolution? The main reason I'm asking is not just in case I want to research into it but also to see if there is in fact a huge basis full of data for evolution that Christians are massively ignorant of.

Some of the better know ones include

Anthropology Journals

American Anthropologist
American Archaeology
American Antiquity
American Journal of Archaeology
American Journal of Human Genetics
Annual Review of Anthropology
Anthropological Papers of the American Museum of Natural History
Antiquity
Archaeology
Archaeometry
Bulletin de la Société Préhistorique Française
Courier Forschungsinstitut Senckenberg
Current Anthropology
Current Research in the Pleistocene
Environmental Archaeology
Evolution and Human Behavior
Folia Primtolgica
Homo
Human Biology
International Journal of Primatology
Journal of Anthropological Archaeology
Journal of Anthropological Research
Journal of Archaeological Method and Theory
Journal of Archaeological Science
Journal of Ecological Anthropology
Journal of Human Evolution
Journal of the Royal Anthropological Institute
Journal of World Prehistory
Lithic Technology
Mankind Quaterly
Maryland Essays in Human Biodiversity
PALAIOS
Palanth
World Archaeology
American Journal of Physical Anthropology
Tree-Ring Bulletin

Biology and General Science Journals

American Journal of Botany
American Journal of Human Genetics
American Museum of Natural History Research Library
American Scientist
Animal Biodiversity and Conservation
Anatomischer Anzeiger
Anatomy, Anthropology, Embryology, and Histology
Annals of Anatomy
Biological Bulletin
Biological Journal of the Linnean Society
Biological Procedures Online
BioMed Central journals
BioScience
Botanical Review
Bulletin of the Ecological Society of America
Canadian Society for Forensic Science Journal
Cell
Chinese Science Bulletin
Comptes Rendus de l’Académie de Sciences
Current Science
Ecological Society of America Journals
European Journal of Cell Biology
Evolution
Evolution: Education and Outreach
Florida Entomologist
Forensic Science International
Genetics
Genome Research
Integrative and Comparative Biology
International Journal of Plant Sciences
Journal of Biological Research
Journal of Biology
Journal of Evolutionary Biology
Journal of Experimental Biology
Journal of Forensic Sciences
Journal of Genetics
Journal of Mammalian Evolution
Journal of Mammalogy
Journal of Molecular Evolution
Journal of Tropical Biology
Maryland Essays in Human Biodiversity
Molecular Biology and Evolution
Molecular Phylogenetics and Evolution
Nature
Natural History
New Scientist
Philosophical Transactions of the Royal Society
Plos: Public Library of Science
Proceedings of the American Philosophical Society
Proceedings of the National Academy of Sciences
Proceedings of the Oklahoma Academy of Science
Proceedings of the Royal Irish Academy
Quarterly Review of Biology
Raffles Bulletin of Zoology
Science
Scientific American
South African Journal of Science
Tentacle
Theoretical Applied Genetics
Transactions of the Royal Society of London
Turkish Journal of Zoology
Zoological Studies

Evolutionary Computation Journals

IEEE Transactions on Evolutionary Computation
IEEE/ACM Transactions on Computational Biology and Bioinformatics
Evolutionary Computation
Applied Soft Computing

Fossil Databases and Paleontology

Database of Lower Vertebrates
Devonian Times
Dinobase
Evolution of Terrestrial Ecosystems
Faunmap
Fish To Amphibian Transition
Fred: The Fossil Record Electronic Database
Green River Paleobotany Project
Insect Fossils and Evolution
Links for Paleobotanists
Mesozoic Eucynodonts
Miomap
Neogene Mammal Database
Neogene Marine Biota of Tropoical America
Oceans of Kansas
The Paleobiology Database
The Paleomap Project
Palaeos: The Trace of Life on Earth
The Panama Paleontology Project
Permian Tetrapods
The Polyglot Paleontologist
Pterosaur Database
Sepkoski’s Online Genus Database
The Therapsids
University Of Kansas Paleontological Institute
University of California Museum of Paleontology Collections
Vertebrate Paleontology Laboratory Collection Database
The Virtual Fossil Museum

Paleontology Journals

Acta Geologica Sinica
Acta Palaeontologica Polonica
Annales de Paléontologie
Carnets de Géologie (Notebooks on Geology)
Cave Archaeology and Paleontology Research Archive
Geoscience and Man
Journal of Paleontological Sciences
Journal of Sedimentary Research
Journal of Systematic Paleontology
Journal of Taphonomy
Journal of Vertebrate Paleontology
Netherlands Journal of Geosciences
PalArch
Paleobiology
Palaeogeography, Palaeoclimatology, Palaeoecology
Palaeontologia Electronica
Palaeontologie Africana
Paleontographica Italica
Quaternary Research
Quaternary Science Review
Vertebrata PalAsiatica

Direct links to them and many other resources for evolutionary knowledge including science blogs, museums, research centers, etc. can be found here

Panda's Thumb Evolutionary Resources

Hope that helps.

- T

[rogue06]

Not much I can add -- especially to Tiggy's extensive list. I will add that many who are skeptical of evolution have a knee-jerk negative reaction to Talk Origins although it really is an excellent resource. As to the books wattsr1 mentioned I would recommend starting with Ken Miller (Only a Theory: Evolution and the Battle for America's Soul and Finding Darwin's God: A Scientist's Search for Common Ground Between God and Evolution) and Francis Collins (The Language of God: A Scientist Presents Evidence for Belief). Both are written from a Christian POV. Personally, I find Miller to be the better writer but that is just my opinion. Also Donald Prothero's Evolution: What the fossils say and why it matters is nothing short of fantastic. There are others, including several that haven't been mentioned (including several from Christians), but these make for an excellent start.

[rogue06]

A new method for identifying different species of dinosaurs has been proprosed which relies upon analyzing preserved skin impressions.

The methodology, developed by Phil R. Bell a paleontologist with the Department of Biological Sciences, University of Alberta in Canada, is established on comparing the differences in scale pattern impressions, which includes such things as scales, feathers, and ossified dermal structures like scutes, that existed between not only different species of various dinosaurs but also on different parts of their bodies.

Bell compared Mongolian hadrosaur fossils discovered in a fossil site known as the “Dragon’s Tomb” in Mongolia’s Nemegt Formation in the early 1950s that had associated with skin impressions with similarly detailed hadrosaur fossils excavated in southern Alberta’s upper Horseshoe Canyon Formation in 1912.

Earlier examinations of the roughly 68 myo (Late Cretaceous) fossilized bones had already determined that these hadrosaurs were from two different species of hadrosaur -- namely Saurolophus angustirostris from Mongolia and Saurolophus osborni from Canada.

Bell was was able to reach the same conclusion by examining the skin impressions preserved in the rock and isolating the subtle but distinctive differences. IOW, Bell had ascertained that the skin of these two different species were dissimilar enough that one species can be easily distinguished from the other.

He found that the differences were most pronounced in the tail region, where the Mongolian hadrosaurs possessed vertical bands of morphologically distinct scales, described as a grid-like arrangement of circular feature-scales, and tabular scales along the dorsal midline.

Of course the reason that the tail displays the largest differences could be due to the fact that by far the most fossilized skin impressions come from this region.

Bell notes that skin impressions have also been found associated with numerous other types of hadrosaurids including Edmontosaurus annectens, Corythosaurus casuarius, Brachylophosaurus canadensis, Parasaurolophus walkeri, Lambeosaurus magnicristatus, and Lambeosaurus lambei along with several other yet unidentified hadrosaurids.

He also points to a few differences in the scales from the shoulder girdle and forelimb of Saurolophus angustirostris in comparison to those seen in other hadrosaurids.

Being able to recognize morphologically distinct scales and scale patterns on different parts of the body means that in the future paleontologists should be careful to take extensive notes of any skin impressions found since a record of such can be used as another tool in a positive identification of a dinosaur.

"It changes the way we are approaching paleontology," Bell said. "Back in the day, it was, 'find as many bones as you can and name as many species as you can.' Now, as the field has matured, people are asking different questions, recognizing these animals as actually living entities rather than curios in a museum."

hadrosaur skin impressions.png
Sections of skin impressions (light gray) on the two species

Further Reading:

Standardized Terminology and Potential Taxonomic Utility for Hadrosaurid Skin Impressions: A Case Study for Saurolophus from Canada and Mongolia Abstract & Paper

Dino-skin study leads to revelations

Judging a Dinosaur By its Cover

How do you get to know a dinosaur? Why by their scales of course

[rogue06]

A new analysis of the extinct Ohmdenia multidentata, a Teleost (Ray-finned) fish that is known from only one specimen found in the Posidonia Shale of Southern Germany and that existed approximately 180 mya (Early Jurassic), has reclassified it as being a Pachycormid rather than a Palaeonisciform as previously thought.

More precisely Ohmdenia is thought to be the sister species to the filter-feeding Pachycormiform (the longest lived radiation of large vertebrate suspension feeders some of which rivaled today's Blue Whales in size), which would make it the closest relative of that group that is not actually a member of it. It is now thought that Ohmdenia's closest living relatives are cod and goldfish.

Why this is important is that it helps to demonstrate that some ancient ray-finned fish became gigantic suspension feeders feeding on plankton by filtering them from the water much like the modern aquatic animals that developed this feeding strategy millions of years later such as baleen whales, whale sharks, basking sharks, manta rays and smaller creatures like paddlefish.

While this isn't exactly news it does show that while these creatures from very different groups independently developed filter feeding they appear to have undergone a similar series of changes as they evolved towards this destination indicating that filter-feeders fill an important ecological niche that animals of one kind or another can be presumed to evolve to exploit.

Ohmdenia was swimming in the seas at the time as the earliest filter-feeding Pachycormiforms and as their closest relative has the potential to shed light on how their ancestors lived.

As the study author, Dr Matt Friedman, a palaeontologist at the University of Oxford's Department of Earth Sciences notes, "This really improves our understanding of how giant suspension feeding evolved; until now it's been based on just one group of animals – the whales."

According to Friedman it seems that most pachycormids were open-ocean predators much like modern tuna and swordfish, but Ohmdenia appears to have been on its way to evolving into a giant suspension feeder.

Unlike most of the non-filter-feeding Pachycormiforms (which possessed needle or blade-shaped teeth) the 2.5 meter (bit over 8') long Ohmdenia's teeth were shorter and blunter, more suited to grasping than cutting or puncturing and of a type usually associated with a diet of soft-bodied ceplapods like belemites (squid-like animals), indicating that shifting to such a diet might have been a stage on the way to filter-feeding.

Further, the jaw of Ohmdenia had already become elongated, reducing their power to bite into prey.

This appears to be the same sequence that many modern filter-feeding creatures took in that in the close extinct relatives of baleen whales the jaws lengthened and teeth became blunter and less pronounced as they transformed from open-ocean predation to eating plankton.

The evidence suggests that these whales had spent a long time on this diet while they were also developing the baleen plates that allows the filtering of plankton from the water. Some fossil whales that still ate larger prey display signs of the network of blood vessels required to sustain the baleen (which is a living tissue constructed of keratin -- the same material as human fingernails and hair).

Ohmdenia.jpg

Further Reading:

Parallel evolutionary trajectories underlie the origin of giant suspension-feeding whales and bony fishes Abstract

Fossil fish illuminates evolution of plankton-eating

Ancient Fish Ohmdenia Receives New Classification

A Pachycormiform Fish from the Lower Jurassic Posidonia Shale

[rogue06]

Portions of a prehistoric tropical peat forest roughly 298 myo (Early Permian) have been unearthed near Wuda, a district on the west bank of the Yellow River of the city of Wuhai, in the Inner Mongolia Autonomous Region of the People's Republic of China.

The location consists of three separate but relatively closely set sites that cover a total of 1000 square meters (about a quarter acre) and has been incredibly well-preserved in volcanic ash that covered the ancient forest in just a few days

The plants were preserved where they fell, often in the exact locations where they grew with the weight of falling ash riping the leaves off of twigs and branches, toppling trees and then finally burying it all.

One of the researchers, paleobotanist Hermann W. Pfefferkorn, a professor at the University of Pennsylvania's Department of Earth and Environmental Science, called the well-preserved fossils entombed in a layer of volcanic ash a "forest Pompeii" and noting that it's only when an area is rapidly preserved in situ that researchers are able to get a true picture of the composition and ecology of it.

Even though floods can cover large portions of sediment in one fell swoop, they also usually wash local organisms out while bringing in organisms from other areas. This is what makes a smothering layer of volcanic ash entombing the area superior for giving the most reliable preservation.

The consistent thickness of ash deposits in the region, as well as the size of individual ash particles, suggest that the volcanic blast occurred more than 100 kilometres away.

Back when the trees were growing this forest sat on the northwestern corner of a large tropical island straddling the equator (along with what is now northeast China and most of Korea) off what was becoming the eastern shore of the still-forming supercontinent of Pangaea.

So far the researchers have identified six different group of trees, many of which were previously known to science. Tree ferns formed a lower canopy while much taller, now-extinct trees or tree-like plants — Sigillaria and Cordaites — soared up to 24m (78½') above the ground.

It also had vines and nearly complete specimens from three species of a group of extinct trees called Noeggerathiales, a little-understood group of small, spore-bearing trees thought to be related to ferns that had been identified from sites in North America and Europe, but seemed to be much more common in these Asian sites.

The researchers also found that the three sites in Wuda were somewhat different from one another in plant composition. For instance at one site the dominant plant type were the Noeggerathiales while at another site they weren't very common.

Pfefferkorn stated that this is the first such forest reconstruction in Asia for any time interval, as well as the first of a peat forest for this time interval and the first with Noeggerathiales as a dominant group.

The paper describing the find was supposed to be released online today in the Proceedings of the National Academy of Sciences (PNAS), but as is not uncommon things aren't running smoothly.



Further Reading:

Ash-covered forest is 'Permian Pompeii'

Study characterizes 300-million-year-old tropical forest preserved in volcano ash

Pompeii-like forest buried in volcanic ash



Hat tip to SteveF over at TalkRational

[rogue06]

Portions of a prehistoric tropical peat forest roughly 298 myo (Early Permian) have been unearthed near Wuda, a district on the west bank of the Yellow River of the city of Wuhai, in the Inner Mongolia Autonomous Region of the People's Republic of China.

The location consists of three separate but relatively closely set sites that cover a total of 1000 square meters (about a quarter acre) and has been incredibly well-preserved in volcanic ash that covered the ancient forest in just a few days

The plants were preserved where they fell, often in the exact locations where they grew with the weight of falling ash riping the leaves off of twigs and branches, toppling trees and then finally burying it all.

One of the researchers, paleobotanist Hermann W. Pfefferkorn, a professor at the University of Pennsylvania's Department of Earth and Environmental Science, called the well-preserved fossils entombed in a layer of volcanic ash a "forest Pompeii" and noting that it's only when an area is rapidly preserved in situ that researchers are able to get a true picture of the composition and ecology of it.

Even though floods can cover large portions of sediment in one fell swoop, they also usually wash local organisms out while bringing in organisms from other areas. This is what makes a smothering layer of volcanic ash entombing the area superior for giving the most reliable preservation.

The consistent thickness of ash deposits in the region, as well as the size of individual ash particles, suggest that the volcanic blast occurred more than 100 kilometres away.

Back when the trees were growing this forest sat on the northwestern corner of a large tropical island straddling the equator (along with what is now northeast China and most of Korea) off what was becoming the eastern shore of the still-forming supercontinent of Pangaea.

So far the researchers have identified six different group of trees, many of which were previously known to science. Tree ferns formed a lower canopy while much taller, now-extinct trees or tree-like plants — Sigillaria and Cordaites — soared up to 24m (78½') above the ground.

It also had vines and nearly complete specimens from three species of a group of extinct trees called Noeggerathiales, a little-understood group of small, spore-bearing trees thought to be related to ferns that had been identified from sites in North America and Europe, but seemed to be much more common in these Asian sites.

The researchers also found that the three sites in Wuda were somewhat different from one another in plant composition. For instance at one site the dominant plant type were the Noeggerathiales while at another site they weren't very common.

Pfefferkorn stated that this is the first such forest reconstruction in Asia for any time interval, as well as the first of a peat forest for this time interval and the first with Noeggerathiales as a dominant group.

The paper describing the find was supposed to be released online today in the Proceedings of the National Academy of Sciences (PNAS), but as is not uncommon things aren't running smoothly.



Further Reading:

Ash-covered forest is 'Permian Pompeii'

Study characterizes 300-million-year-old tropical forest preserved in volcano ash

Pompeii-like forest buried in volcanic ash



Hat tip to SteveF over at TalkRational

Abstract & Paper now available: Permian vegetational Pompeii from Inner Mongolia and its implications for landscape paleoecology and paleobiogeography of Cathaysia