Scientists Find Oldest Dinosaur — Or Closest Relative Yet
ScienceDaily (Dec. 4, 2012) — Researchers have discovered what may be the earliest dinosaur, a creature the size of a Labrador retriever, but with a five foot-long tail, that walked the Earth about 10 million years before more familiar dinosaurs like the small, swift-footed Eoraptor and Herrerasaurus.
The findings mean that the dinosaur lineage appeared 10 million to 15 million years earlier than fossils previously showed, originating in the Middle Triassic rather than in the Late Triassic period.
“If the newly named Nyasasaurus parringtoni is not the earliest dinosaur, then it is the closest relative found so far,” according to Sterling Nesbitt, a University of Washington postdoctoral researcher in biology and lead author of a paper published online Dec. 5 in Biology Letters, a journal of the United Kingdom’s Royal Society.
“For 150 years, people have been suggesting that there should be Middle Triassic dinosaurs, but all the evidence is ambiguous,” he said. “Some scientists used fossilized footprints, but we now know that other animals from that time have a very similar foot. Other scientists pointed to a single dinosaur-like characteristic in a single bone, but that can be misleading because some characteristics evolved in a number of reptile groups and are not a result of a shared ancestry.”
The researchers had one humerus — or upper arm bone — and six vertebrae to work with. They determined that the animal likely stood upright, measured 7 to 10 feet in length (2 to 3 meters), was as tall as 3 feet at the hip (1 meter) and may have weighed between 45 and 135 pounds (20 to 60 kilograms).
The fossilized bones were collected in the 1930s from Tanzania, but it may not be correct to say dinosaurs originated in that country. When Nyasasaurus parringtoni lived, the world’s continents were joined in the landmass called Pangaea. Tanzania would have been part of Southern Pangaea that included Africa, South America, Antarctica and Australia.
“The new findings place the early evolution of dinosaurs and dinosaur-like reptiles firmly in the southern continents,” said co-author Paul Barrett at the Natural History Museum, London.
The bones of the new animal reveal a number of characteristics common to early dinosaurs and their close relatives. For example, the bone tissues in the upper arm bone appear as if they are woven haphazardly and not laid down in an organized way. This indicates rapid growth, a common feature of dinosaurs and their close relatives.
“We can tell from the bone tissues that Nyasasaurus had a lot of bone cells and blood vessels,” said co-author Sarah Werning at the University of California, Berkeley, who did the bone analysis. “In living animals, we only see this many bone cells and blood vessels in animals that grow quickly, like some mammals or birds.”
“The bone tissue of Nyasasaurus is exactly what we would expect for an animal at this position on the dinosaur family tree,” she added. “It’s a very good example of a transitional fossil; the bone tissue shows that Nyasasaurus grew about as fast as other primitive dinosaurs, but not as fast as later ones.”
Another example is the upper arm bone’s distinctively enlarged crest, needed to anchor the upper arm muscles. The feature, known as an elongated deltopectoral crest, is also common to all early dinosaurs.
“Nyasasaurus and its age have important implications regardless of whether this taxon is a dinosaur or the closest relatives of dinosaurs,” Nesbitt said. “It establishes that dinosaurs likely evolved earlier than previously expected and refutes the idea that dinosaur diversity burst onto the scene in the Late Triassic, a burst of diversification unseen in any other groups at that time.”
It now appears that dinosaurs were just part of a large diversification of archosaurs. Archosaurs were among the dominant land animals during the Triassic period 250 million to 200 million years ago and include dinosaurs, crocodiles and their kin.
“Dinosaurs are just part of this archosaur diversification, an explosion of new forms soon after the Permian extinction,” Nesbitt said.
The specimen used to identify the new species is part of the collection at the Natural History Museum, London. Four vertebrae from a second specimen of Nyasasaurus, which were also used in this research, are housed in the South African Museum in Cape Town. The work was funded by the National Science Foundation and the Natural History Museum, London. The fourth co-author on the paper is Christian Sidor, UW professor of biology.
The name Nyasasaurus parringtoni is new, but “Nyasasaurus” — combining the lake name Nyasa with the term “saurus” for lizard — is not. The late paleontologist Alan Charig, included as a co-author on the paper, named the specimen but never documented or published in a way that was formally recognized. “Parringtoni” is in honor of University of Cambridge’s Rex Parrington, who collected the specimens in the 1930s.
“What’s really neat about this specimen is that it has a lot of history. Found in the ’30s, first described in the 1950s but never published, then its name pops up but is never validated. Now 80 years later, we’re putting it all together,” Nesbitt said.
“This work highlights the important role of museums in housing specimens whose scientific importance might be overlooked unless studied and restudied in detail,” Barrett said. “Many of the more important discoveries in paleontology are made in the lab, or museum storerooms, as well as in the field.”
New Ancient Shark Species Gives Insight Into Origin of Great White
ScienceDaily (Nov. 14, 2012) — The great white shark is one of the largest living predatory animals and a magnet for media sensationalism, yet its evolutionary history is as misunderstood as its role as a menace.
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Originally classified as a direct relative of megatooth sharks, the white shark’s evolutionary history has been debated by paleontologists for the last 150 years. In a study appearing in print and online today in the journal Palaeontology, University of Florida researchers name and describe an ancient intermediate form of the white shark, Carcharodon hubbelli, which shows the modern white shark likely descended from broad-toothed mako sharks. The study deviates from the white shark’s original classification as a relative of megatooth sharks such as the extinct Carcharocles megalodon, the largest carnivorous shark that ever lived.
Based on recalibrated dates of the excavation site in Peru, the study also concludes the new species was about 2 million years older than previously believed.
“We can look at white sharks today a little bit differently ecologically if we know that they come from a mako shark ancestor,” said lead author Dana Ehret, a lecturer at Monmouth University in New Jersey who conducted research for the study as a UF graduate student. “That 2-million-year pushback is pretty significant because in the evolutionary history of white sharks, that puts this species in a more appropriate time category to be ancestral or kind of an intermediate form of white shark.”
Most ancient shark species are named using isolated teeth, but analysis of C. hubbelli, also known as Hubbell’s white shark, was based on a complete set of jaws with 222 teeth intact and 45 vertebrae. The species was named for Gainesville resident Gordon Hubbell, a collector who recovered the fossils from a farmer who discovered them in the Pisco Formation of southern Peru in 1988. Hubbell donated the specimens to the Florida Museum of Natural History on the UF campus in December 2009.
“The impetus of this project was really the fact that Gordon Hubbell donated a majority of his fossil shark collection to the Florida Museum,” Ehret said. “Naming the shark in his honor is a small tip of the hat to all the great things he has done to advance paleontology.”
Ehret and co-authors published an initial study describing the shark specimens in the Journal of Vertebrate Paleontology in 2009, but dates for the site reflected information from a 1985 study about the Pisco Formation, he said. With Hubbell’s hand-drawn maps and descriptions of the landscape, researchers returned to the site and found the exact spot the fossils were discovered.
Scientists extracted more accurate age estimates from mollusk shells in the fossil horizon to determine the shark species was from the late Miocene, about 6.5 million years ago, rather than the early Pliocene, about 4.5 million years ago. The new dates will also be useful for better understanding other fossils found in the rich Pisco Formation, which include new whale, marine sloth and terrestrial vertebrate species.
“The thing that was remarkable to me was that these fossils came from right out in the desert and this was before GPS, so Dana had only an approximate notion of where it was,” said Florida Museum of Natural History Director Douglas Jones, a study co-author who conducted strontium isotope dating of the fossils. “But after a few days of looking, we were able to find this deposit and Dana found the rest of the missing shark’s teeth.”
Researchers determined Hubbell’s white shark was related to ancient broad-toothed mako sharks by comparing the physical shapes of shark teeth to one another. While modern white sharks have serrations on their teeth for consuming marine mammals, mako sharks do not have serrations because they primarily feed on fish. Hubbell’s white shark has coarse serrations indicative of a transition from broad-toothed mako sharks to modern white sharks.
These evolutionary relationships have been hypothesized for decades, and researchers who interpret modern white sharks as being more closely related to megatooth sharks say it is “a friendly disagreement,” according to Michael Gottfried, an associate professor in geological sciences at Michigan State University.
But shark expert David Ward, a research associate at the Natural History Museum, London, said “fewer people believe the big megatooth sharks are related to the great white sharks than believe the Earth is flat.”
“Everyone working within the field will be absolutely delighted to see this relationship formalized,” Ward said.
Study co-authors include Bruce MacFadden of the Florida Museum, Thomas DeVries of the Burke Museum of Natural History and Culture in Seattle, David Foster of UF and Rodolfo Salas-Gismondi of Museo de Historia Natural Javier Prado in Lima.
Date of Earliest Animal Life Reset by 30 Million Years
ScienceDaily (June 28, 2012) — University of Alberta researchers have uncovered physical proof that animals existed 585 million years ago — 30 million years earlier than previous records show.
The discovery was made by U of A geologists Ernesto Pecoits and Natalie Aubet in Uruguay. They found fossilized tracks a centimeter-long, slug-like animal left behind 585 million years ago in silty, shallow-water sediment.
A team of U of A researchers determined that the tracks were made by a primitive animal called a bilaterian, which is distinguished from other non-animal, simple life forms by its symmetry — its top side is distinguishable from its bottom side — and a unique set of “footprints.”
U of A paleontologist Murray Gingras says fossilized tracks indicate that the soft-bodied animal’s musculature enabled it to move through the sediment on the shallow ocean floor. “The pattern of movement indicates an evolutionary adaptation to search for food, which would have been organic material in the sediment,” he said.
There were no fossilized remains of a bilaterian’s body, just its tracks. “Generally when we find tracks of a soft-bodied animal, it means there’s no trace of the body because they fossilize under different conditions,” said Gingras. “It’s usually just the body or just the tracks, not both.”
It took more than two years for the U of A team members to satisfy themselves and a peer review panel of scientists that they had the right age for the bilaterian fossils.
U of A geochronologist Larry Heaman was among a group that returned to Uruguay to collect more fossil samples locked in a layer of sandstone. Heaman says because the depositional age of the sandstone is difficult to determine, they focused their investigation on particles of granitic rock found invading the sandstone samples.
Heaman explains that the granitic rocks were put through the university’s mass spectrometry equipment, a process in which samples are bombarded by laser beams and the resulting atom- to molecule-sized particles are analyzed and dated.
Over the course of his U of A career, Heaman has taken part in a number of breakthrough research projects involving fossils. Last year he got the attention of the paleontology world when he confirmed the surprising date of a fossilized dinosaur bone found in New Mexico. Using U of A equipment, Heaman determined that the bone came from a sauropod, a plant-eating dinosaur that was alive some 700,000 years after the mass-extinction event that many believe wiped out all dinosaur life on Earth.
Heaman says the challenge in dating the bilaterian fossil makes it stand out from his other work. “This was the top research accomplishment because it has more direct relevance to the evolution of life as we know it,” he said. “It was such a team effort; any one of us on our own couldn’t have done this.”
Before the U of A bilaterian find, the oldest sign of animal life was dated at 555 million years ago, from a find made in Russia.
Kurt Konhauser, a U of A geomicrobiologist, says the team’s discovery will prompt new questions about the timing of animal evolution and the environmental conditions under which they evolved.
“This research was a huge interdisciplinary effort and shows the depth of the research capabilities here at the U of A,” said Konhauser. “The challenge brought the sciences of geology, paleontology, geomicrobiology and geochronology together to nail down the age of the fossils.”
Konhauser explains that in the past, research into the earliest signs of animal life would typically shift the date back by a few million years, but the U of A’s finding of 30 million years is a real breakthrough.
The U of A’s research team includes Ernesto Pecoits, Natalie Aubet, Kurt Konhauser, Larry Heaman, Richard Stern and Murray Gingras. The research was published June 28 in the journal Science.
Newly Discovered Dinosaur Implies Greater Prevalence of Feathers; Megalosaur Fossil Represents First Feathered Dinosaur Not Closely Related to Birds
ScienceDaily (July 2, 2012) — A new species of feathered dinosaur discovered in southern Germany is further changing the perception of how predatory dinosaurs looked. The fossil of Sciurumimus albersdoerferi,which lived about 150 million years ago, provides the first evidence of feathered theropod dinosaurs that are not closely related to birds.
The fossil is described in a paper published in the Proceedings of the National Academy of Sciences on July 2.
“This is a surprising find from the cradle of feathered dinosaur work, the very formation where the first feathered dinosaur Archaeopteryx was collected over 150 years ago,” said Mark Norell, chair of the Division of Palaeontology at the American Museum of Natural History and an author on the new paper along with researchers from Bayerische Staatssammlung für Paläontologie und Geologie and the Ludwig Maximilians University.
Theropods are bipedal, mostly carnivorous dinosaurs. In recent years, scientists have discovered that many extinct theropods had feathers. But this feathering has only been found in theropods that are classified as coelurosaurs, a diverse group including animals likeT. rexand birds. Sciurumimus — identified as a megalosaur, nota coelurosaur — is the first exception to this rule. The new species also sits deep within the evolutionary tree of theropods, much more so than coelurosaurs, meaning that the species that stem from Sciurumimus are likely to have similar characteristics.
“All of the feathered predatory dinosaurs known so far represent close relatives of birds,” said palaeontologist Oliver Rauhut, of the Bayerische Staatssammlung für Paläontologie und Geologie. “Sciurumimus is much more basal within the dinosaur family tree and thus indicates that all predatory dinosaurs had feathers.”
The fossil, which is of a baby Sciurumimus, was found in the limestones of northern Bavaria and preserves remains of a filamentous plumage, indicating that the whole body was covered with feathers. The genus name ofSciurumimus albersdoerferirefers to the scientific name of the tree squirrels,Sciurus, and means “squirrel-mimic”-referring to the especially bushy tail of the animal. The species name honours the private collector who made the specimen available for scientific study.
“Under ultraviolet light, remains of the skin and feathers show up as luminous patches around the skeleton,” said co-author Helmut Tischlinger, from the Jura Museum Eichstatt.
Sciurumimusis not only remarkable for its feathers. The skeleton, which represents the most complete predatory dinosaur ever found in Europe, allows a rare glimpse at a young dinosaur. Apart from other known juvenile features, such as large eyes, the new find also confirmed other hypotheses.
“It has been suggested for some time that the lifestyle of predatory dinosaurs changed considerably during their growth,” Rauhut said. “Sciurumimus shows a remarkable difference to adult megalosaurs in the dentition, which clearly indicates that it had a different diet.”
Adult megalosaurs reached about 20 feet in length and often weighed more than a ton. They were active predators, which probably also hunted other large dinosaurs. The juvenile specimen of Sciurumimus, which was only about 28 inches in length, probably hunted insects and other small prey, as evidenced by the slender, pointed teeth in the tip of the jaws.
“Everything we find these days shows just how deep in the family tree many characteristics of modern birds go, and just how bird-like these animals were,” Norell said. “At this point it will surprise no one if feather like structures were present in the ancestors of all dinosaurs.
Feathered Saurians: Downy Dinosaur Discovered
ScienceDaily (July 3, 2012) — The new fossil find from the chalk beds of the Franconian Jura evokes associations with a pet cemetery, for the young predatory dinosaur reveals clear traces of fluffy plumage. It also poses an intriguing question: Were all dinosaurs dressed in down?
The fossil of the fledgling saurian, probably newly hatched when it met its end, is remarkable in many ways. First of all, juveniles are extremely rare in the dinosaur fossil record, so every new discovery provides insights into dinosaur nurseries. Moreover, this specimen is perhaps the best-preserved predatory dinosaur that has yet been found in Europe. And Sciurimimus albersdoerferi, which lived during the Jurassic Period some 150 million years ago, displays one very striking feature — its whole body must have been covered with a thick plumage of feathers.
All the feathered dinosaurs so far described belonged to the lineage that gave rise to modern birds. “However, Sciurumimus belongs to a much older branch of the family tree of predatory dinosaurs,” says LMU paleontologist Dr. Oliver Rauhut, who is also affiliated with the Bavarian State Collection for Paleontology and Geology, and led the investigation into the structure and affinities of the sensational new find. “Its plumage may be telling us that all predatory dinosaurs had feathers.”
Were all dinos decked out with feathers?
Several fossil finds have revealed that the pterosaurs — which were capable of flight and are the closest relatives of the dinosaurs — bore hair-like plumage on their bodies. Their fluffy coats resemble the downy feathers that can be recognized in the new fossil. This observation is very significant, as it suggests to the researchers that not just the pterosaurs and the predatory dinosaurs, but all dinosaurs may have had feathers. “If that is the case, we must abandon all our notions about giant reptiles encased in tough scales,” Rauhut says.
As the German-American research team led by Rauhut has been able to show, the new specimen represents a young megalosaur. The genus name Sciurumimus means “squirrel-like” and refers to the animal’s bushy tail, while the species designation albersdoerferi honors the private collector who made the fossil available for scientific study. “When the skeleton was irradiated with UV light, we were able to discern fragments of the skin and the plumage as fluorescent spots and filaments,” says co-author Dr. Helmut Tischlinger.
Cute little dino kids The juvenile Sciurumimus tells us even more. For instance, as in the case of other dinosaurs, its eyes were proportionately much larger than those of adult animals. In other words, young dinosaurs conformed to the “babyface” model. Secondly, it has long been suspected that not just the form of a dinosaur’s face, but also its whole mode of life, was subject to change during lifetime. “And indeed, this individual has a very different set of teeth from those found in adult megalosaurs,” says Rauhut. “That enables us to conclude that their diets also changed as they got older.”
The young Sciurumimus, with its slender, pointed teeth probably preyed on insects and small animals. Fully grown megalosaurs, on the other hand, often exceeded 6 m in length and may have weighed more than a ton, and could give other large dinosaurs a good run for their money. That may also be true of the new species. “We know that dinosaurs were able to grow at terrific rates; diminutive hatchlings could reach adult lengths of several meters,” Rauhut points out. “And even if they might have looked fluffy, they were certainly among the top predators in the food chain.”
The study was financially supported by the Volkswagen Foundation and the American Museum of Natural History
Earliest Record of Mating Fossil Vertebrates: Nine Pairs of Fossilized Turtles Died While Mating 47 Million Years Ago
ScienceDaily (June 20, 2012) — The fossil record consists mostly of the fragmentary remains of ancient animals and plants. But some finds can provide spectacular insights into the life and environment of ancient organisms. The Messel Fossil Pit, a UNESCO world heritage site south of Frankfurt in western Germany, is well known for yielding fossils of unusual quality, including early horses complete with embryos and insects and birds with fossilized colors.
In the latest edition of Biology Letters, a group of scientists lead by Dr. Walter Joyce of the University of Tübingen announces the discovery at Messel of nine pairs of fossilized turtles that perished in the act of mating. Dr. Joyce, a geoscientist from the University of Tübingen, heads the discovery team which includes researchers from the Senckenberg Research Institute Frankfurt and the Hessische Landesmuseum Darmstadt.
“Scientists have collected tens of thousands of fossils at this site in recent decades,” notes co-author Dr. Stephan Schaal of the Senckenberg Naturmuseum in Frankfurt, “but only these turtles are known to occur in pairs, a total of nine so far.” Detailed analysis of the fossil material revealed that each pair consists of a female and male individual. More importantly, even though the males typically face away from the females, the tail of some male individuals can be found wrapped under the shell of the female. “There is no doubt in my mind,” says Dr. Joyce, “These animals died some 47 million years ago in the act of mating. No other vertebrates are known to have died during this important biological process and then been fossilized.”
Most scientists agree that the Messel Pit Fossil Site originated as a deep volcanic crater lake that preserved animals and plants that sank to its bottom, but some questions remain, such as whether the lake had poisonous surface or only subsurface waters. Modern relatives of the fossil turtles found at Messel have permeable skin that allows them to breathe and stay under water for a long time. However, this adaptation can become lethal if these turtles enter poisonous waters. The very fact that turtles were seeking to reproduce at Messel reveals that the surface waters of the volcanic lake supported a thriving biotope. Numerous turtles apparently died, however, when they accidentally sank into poisonous sub-surface waters while mating.
Ancient Giant Turtle Fossil Was Size of Smart Car
ScienceDaily (May 17, 2012) — Picture a turtle the size of a Smart car, with a shell large enough to double as a kiddie pool. Paleontologists from North Carolina State University have found just such a specimen — the fossilized remains of a 60-million-year-old South American giant that lived in what is now Colombia.
he turtle in question is Carbonemys cofrinii, which means “coal turtle,” and is part of a group of side-necked turtles known as pelomedusoides. The fossil was named Carbonemys because it was discovered in 2005 in a coal mine that was part of northern Colombia’s Cerrejon formation. The specimen’s skull measures 24 centimeters, roughly the size of a regulation NFL football. The shell which was recovered nearby — and is believed to belong to the same species — measures 172 centimeters, or about 5 feet 7 inches, long. That’s the same height as Edwin Cadena, the NC State doctoral student who discovered the fossil.
“We had recovered smaller turtle specimens from the site. But after spending about four days working on uncovering the shell, I realized that this particular turtle was the biggest anyone had found in this area for this time period — and it gave us the first evidence of giantism in freshwater turtles,” Cadena says.
Smaller relatives of Carbonemys existed alongside dinosaurs. But the giant version appeared five million years after the dinosaurs vanished, during a period when giant varieties of many different reptiles — including Titanoboa cerrejonensis, the largest snake ever discovered — lived in this part of South America. Researchers believe that a combination of changes in the ecosystem, including fewer predators, a larger habitat area, plentiful food supply and climate changes, worked together to allow these giant species to survive. Carbonemys’ habitat would have resembled a much warmer modern-day Orinoco or Amazon River delta.
In addition to the turtle’s huge size, the fossil also shows that this particular turtle had massive, powerful jaws that would have enabled the omnivore to eat anything nearby — from mollusks to smaller turtles or even crocodiles.
Thus far, only one specimen of this size has been recovered. Dr. Dan Ksepka, NC State paleontologist and research associate at the North Carolina Museum of Natural Sciences, believes that this is because a turtle of this size would need a large territory in order to obtain enough food to survive. “It’s like having one big snapping turtle living in the middle of a lake,” says Ksepka, co-author of the paper describing the find. “That turtle survives because it has eaten all of the major competitors for resources. We found many bite-marked shells at this site that show crocodilians preyed on side-necked turtles. None would have bothered an adult Carbonemys, though — in fact smaller crocs would have been easy prey for this behemoth.”
The paleontologists’ findings appear in the Journal of Systematic Palaeontology. Dr. Carlos Jaramillo from the Smithsonian Tropical Research Institute in Panama and Dr. Jonathan Bloch from the Florida Museum of Natural History contributed to the work. The research was funded by grants from the Smithsonian Institute and the National Science Foundation
Old Fish Makes New Splash: Coelacanth Find Rewrites History of the Ancient Fish
ScienceDaily (May 2, 2012) — Coelacanths, an ancient group of fishes that were once thought to exist only in fossils, made headlines in 1938 when one of their modern relatives was pulled alive from the ocean. Now coelacanths are making another splash — and University of Alberta researchers are responsible for the discovery.
Lead U of A researcher Andrew Wendruff identified coelacanth fossils that he says are so dramatically different from previous finds, they shatter the theory that coelacanth evolution was stagnant in that their body shape and lifestyle changed little since the origin of the group.
Wendruff says his one-metre-long, fork-tailed coelacanth was one of an “offshoot” lineage that lived 240 million years ago. It falls between the earliest coelacanth fossils dating back 410 million years and the latest fossils dated about 75 million years ago, near the end of the age of dinosaurs.
“Our coelacanth had a forked tail, indicating it was a fast-moving, aggressive predator, which is very different from the shape and movement of all other coelacanths in the fossil record,” said Wendruff.
The researchers say all other ancient coelacanth fossils, and even the modern living coelacanths, have very different bodies.
The first modern coelacanth, or “living fossil,” was captured 74 years ago off the coast of South Africa. Since then, others have been caught in southern oceans near the Comoros Islands, Tanzania and Indonesia.
The fork-tailed fossils described by the U of A team were found in the Rocky Mountains near Tumbler Ridge, British Columbia. Wilson says the eastern range of the Rockies 240 million years ago was a very different place from what it is today. “The area was underwater, lying off the western coast of the supercontinent Pangaea.”
Wendruff’s research co-author, U of A professor emeritus Mark Wilson, describes typical coelacanths as having chunky bodies, fins of varying size and broad, flexible tails. “These fish were slow-moving and probably lay in wait for their prey,” said Wilson.
Wendruff’s coelacanth is so different from all others that it’s been given its own name, Rebellatrix, which means “rebel coelacanth.” The researchers say Rebellatrix came along after the end-Permian mass extinction 250 million years ago, an event so lethal it wiped out 90 per cent of marine life.
Rebellatrix filled a previously occupied predator niche, but it didn’t fare well.
“Rebellatrix was likely a spectacular failure in the evolution of cruising predation,” said Wendruff. “Clearly, some other fish groups with forked tails must have outperformed this coelacanth, as it does not appear later in the fossil record.” Wilson notes that one group of fishes that may have outperformed Rebellatrix were sharks, fossils of which were found in the same rocks.
The research by Wendruff and Wilson was published May 2 as the cover article in the Journal of Vertebrate Paleontology.
Floor of Oldest Fossilized Forest Discovered: 385 Million Years Old
ScienceDaily (Mar. 1, 2012) — Scientists from Binghamton University and Cardiff University, and New York State Museum researchers, and have reported the discovery of the floor of the world’s oldest forest in a cover article in the March 1 issue of Nature.
“It was like discovering the botanical equivalent of dinosaur footprints,” said Dr. William Stein, associate professor of biological sciences at Binghamton University, and one of the article’s authors. “But the most exciting part was finding out just how many different types of footprints there were. The newly uncovered area was preserved in such a way that we were literally able to walk among the trees, noting what kind they were, where they had stood and how big they had grown.”
Scientists are now piecing together a view of this ancient site, dating back about 385 million years ago, which could shed new light on the role of modern-day forests and their impact on climate change.
The recent discovery was made in the same area in Schoharie County where fossils of Earth’s oldest trees — the Gilboa stumps — were discovered in the 1850s, 1920 and again in 2010 and were brought to the State Museum. The Museum has the world’s largest and best collection of Gilboa fossil tree stumps. For decades scientists did not know what the trees connected to the stumps looked like. That mystery was solved when Linda VanAller Hernick, the State Museum’s Paleontology collections manager, and Frank Mannolini, Paleontology collections technician, found fossils of the tree’s intact crown in a nearby location in 2004, and a 28-foot-long trunk portion in 2005. Mannolini, Hernick, and Dr. Christopher M. Berry, a paleobotany lecturer at Cardiff University in Wales, co-authored a Nature article reporting that discovery, as well as the most recent one. Working in conjunction with Stein, Mannolini also developed a sketch of the ancient forest.
“This spectacular discovery and the resulting research provide more answers to the questions that have plagued scientists for more than a century since the first Gilboa stumps were uncovered and brought to the State Museum,” said Hernick, whose passionate interest in the fossils date back to her childhood exposure to the Gilboa fossils. In 2003 Hernick wrote The Gilboa Fossils, a book published by the State Museum, about the history and significance of the fossils and their use in an iconic exhibition about the Earth’s oldest forest that was in the Museum’s former location in the State Education Department building on Washington Avenue. One of the key planners of the exhibition, which influenced generations of paleontologists, was Winifred Goldring, the nation’s first female state paleontologist who was based at the State Museum. She worked tirelessly to study and interpret the Gilboa fossils and named the trees Eospermatopteris, or “ancient seed fern.” In 1924, her paper about the stumps, together with the Museum exhibition, brought the “Gilboa forest” to the attention of the world. One of the Gilboa stumps will be on display in the Museum lobby, beginning March 2. Following the discovery of the tree’s crown, a thorough investigation was conducted by Stein and Dr. Christopher M. Berry, a paleobotany lecturer at Cardiff University in Wales and the other co-author of both Nature articles. They were able to determine that these trees actually resembled modern-day cycads or tree ferns, but interestingly enough, were not related to either one. Many questions still remained about what the surrounding area looked like, whether other plant life co-existed with these trees and how.
In 2010, during ongoing repair of the Gilboa Dam, New York City Department of Environmental Protection (DEP) engineers excavated infill from a quarry in Schoharie County. They agreed to allow researchers to re-examine the site where the fossils had been found when the dam was built in the 1920s. What they found this time was a large, substantially intact portion of the ancient forest horizon, complete with root systems. As they had expected, Eospermatopteris root systems of different sizes were the most abundant. But what they didn’t expect to find was the level of detail of the overall composition of the forest.
The first glimpse of the unexpected complexity of this ancient forest came when Stein, Berry, Hernick and Mannolini found the remains of large scrambling tree-sized plants, identified as aneurophytaleans. These plants were likely close ecological associates to the original trees, living among them on the forest floor like modern ferns, possibly scrambling into the forest canopy much as tropical vines do today. The aneurophytes are the first in the fossil record to show true “wood” and the oldest known group in the lineage that lead to modern seed plants.
Work on the new discoveries also pointed to the vital importance that the State Museum’s collections have played in the paleontological research. “Discovery of scrambling aneurophytaleans at Gilboa was a complete surprise, but pointed to the likelihood that similar material had already been found at the site, but was unrecognized,” said Hernick. “Sure enough in the State Museum collections a wonderful specimen, originally collected in the 1920s, provided additional key evidence.”
The team also came across a tree belonging to the class Lycopsida, or club mosses, which predates an earlier discovery made in Naples, NY and an ecologically important group in the history of land plants. The lycopsids are an ancient group of non-seed plants represented today by low growing forms such as the “running pines” of the northern hardwood forests of New York. They also inhabited swamps and ended up being much of the Pennsylvanian coal we burn today.
Based on the new research, the team now believes that the area probably enjoyed a wetland environment in a tropical climate. It was filled with large Eospermatopteris trees that resembled weedy, hollow, bamboo-like plants, with roots spreading out in all directions, allowing other plants to gain a foothold. Scrambling among these roots on the forest floor were aneurophytaleans, acting much like ferns do today, and possibly climbing into the forest canopy as vines. The lycopsids, although seemingly rare, may also have been very important in certain places although perhaps not yet as specialized inhabitants of swamps.
But what the research team believes is most important about this particular site is what it was doing to impact the rest of the planet. At the time the Gilboa forest began to emerge — during the Middle Devonian period, about 385 million years ago — Earth experienced a dramatic drop in global atmospheric carbon dioxide levels and the associated cooling led ultimately to a period of glaciation.
“Trees probably changed everything,” said Stein. “Not only did these emerging forests likely cause important changes in global patterns of sedimentation, but they may have triggered a major extinction in fossil record.”
For Stein, it all comes down to one thing — how much we don’t know but need to understand about our ancient past. “The complexity of the Gilboa site can teach us a lot about the original assembly of our modern day ecosystems,” said Stein. “As we continue to understand the role of forests in modern global systems, and face potential climate change and deforestation on a global scale, these clues from the past may offer valuable lessons for managing our planet’s future.”
T. Rex Has Most Powerful Bite of Any Terrestrial Animal Ever
ScienceDaily (Feb. 28, 2012) — Research at the University of Liverpool, using computer models to reconstruct the jaw muscle of Tyrannosaurus rex, has suggested that the dinosaur had the most powerful bite of any living or extinct terrestrial animal.
The team artificially scaled up the skulls of a human, alligator, a juvenile T. rex, and Allosaurus to the size of an adult T. rex. In each case the bite forces increased as expected, but they did not increase to the level of the adult T. rex, suggesting that it had the most powerful bite of any terrestrial animal.
Previous studies have estimated that T. rex‘s bite had a force of 8,000 to 13,400 Newtons, but given the size of the animal, thought to weigh more than 6,000kg, researchers suspected that its bite may have been more powerful than this. Liverpool scientists developed a computer model to reverse engineer the animal’s bite, a method that has previously been used to predict dinosaur running speeds.
An animal’s bite force is largely determined by the size of the jaw muscles. Using their computer models, researchers tested a range of alternative muscle values, as it is not precisely known what the muscles of dinosaurs were like. Even with error margins factored in, the computer model still showed that the T. rex had a more powerful bite than previously suggested.
The smallest values predicted were around 20,000 Newtons, while the largest values were as high as 57,000 Newtons, which would be equivalent to the force of a medium sized elephant sitting down on the ground.
Researchers also found that the results for the juvenile T. rex had a relatively the weaker bite than the adult T. rex, even when size differences and uncertainties about muscle size were taken into account. The large difference between the two measurements, despite the error margins factored in, may suggest that T. rex underwent a change in feeding behaviour as it grew.
Dr Karl Bates, from the University’s Department of Musculoskeletal Biology, said: “The power of the T. rex jaw has been a much debated topic over the years. Scientists only have the skeleton to work with, as muscle does not survive with the fossil, so we often have to rely on statistical analysis or qualitative comparisons to living animals, which differ greatly in size and shape from the giant enigmatic dinosaurs like T. rex. As these methods are somewhat indirect, it can be difficult to get an objective insight into how dinosaurs might have functioned and what they may or may not have been capable of in life.
“To build on previous methods of analysis, we took what we knew about T. rex from its skeleton and built a computer model that incorporated the major anatomical and physiological factors that determine bite performance. We then asked the computer model to produce a bite so that we could measure the speed and force of it directly. We compared this to other animals of smaller body mass and also scaled up smaller animals to the size of T. rex to compare how powerful it was in relative terms.
“Our results show that the T. rex had an extremely powerful bite, making it one of the most dangerous predators to have roamed our planet. Its unique musculoskeletal system will continue to fascinate scientists for years to come.”