Thursday, October 25, 2012

100-Million-Year-Old Coelacanth Fish Discovered in Texas Is New Species from Cretaceous.

Source: ScienceDaily
ScienceDaily (Oct. 24, 2012) — A new species of coelacanth fish has been discovered in Texas. The species is now the youngest coelacanth from Texas; fish jaw and cranial material indicate a new family -- Dipluridae -- that was evolutionary transition between two previously known families.
Pieces of tiny fossil skull found in Fort Worth have been identified as 100 million-year-old coelacanth bones, according to paleontologist John F. Graf, Southern Methodist University, Dallas.
The coelacanth has one of the longest lineages -- 400 million years -- of any animal. It is the fish most closely related to vertebrates, including humans.
The SMU specimen is the first coelacanth in Texas from the Cretaceous, said Graf, who identified the fossil. The Cretaceous geologic period extended from 146 million years ago to 66 million years ago.
Graf named the new coelacanth species Reidus hilli.
Coelacanths have been found on nearly every continent
Reidus hilli is now the youngest coelacanth identified in the Lone Star State.
Previously the youngest was a 200 million-year-old coelacanth from the Triassic. Reidus hilli is the first coelacanth ever identified from the Dallas-Fort Worth area.
Coelacanth fossils have been found on every continent except Antarctica. Few have been found in Texas, Graf said.
The coelacanth fish has eluded extinction for 400 million years. Scientists estimate the coelacanth reached its maximum diversity during the Triassic.
The coelacanth was thought to have gone extinct about 70 million years ago. That changed, however, when the fish rose to fame in 1938 after live specimens were caught off the coast of Africa. Today coelacanths can be found swimming in the depths of the Indian Ocean.
Chart courtesy of the British Geological Survey.
Closest living fish to all vertebrates alive on land "
These animals have one of the longest lineages of any vertebrates that we know," Graf said.
The SMU specimen demonstrates there was greater diversity among coelacanths during the Cretaceous than previously known.
"What makes the coelacanth interesting is that they are literally the closest living fish to all the vertebrates that are living on land," he said. "They share the most recent common ancestor with all of terrestrial vertebrates."
Coelacanths have boney support in their fins, which is the predecessor to true limbs.
"Boney support in the fins allows a marine vertebrate to lift itself upright off the sea floor," Graf said, "which would eventually lead to animals being able to come up on land."
Texas coelacanth, Reidus hilli, represents a new species and a new family
Graf identified Reidus hilli from a partial skull, including gular plates, which are bones that line the underside of the jaw.
"Coelacanths are not the only fish that have gular plates, but they are one of the few that do," Graf said. "In fact, the lenticular shape of these gular plates is unique to coelacanths. That was the first indicator that we had a fossil coelacanth."
Reidus hilli was an adult fish of average size for the time in which it lived, said Graf. While modern coelacanths can grow as large as 3 meters, Reidus hilli was probably no longer than 40 centimeters. Its tiny skull is 45 millimeters long by 26 millimeters wide, or about 1.75 inches long by 1 inch wide.
Reidus hilli's total body size is typical of the new family of coelacanths, Dipluridae, which Graf describes and names. He chose the name for the least primitive coelacanth in the family, Diplurus, which lived during the Triassic.
"Reidus hilli helped me tie a group of coelacanths together into what I identify as a new family of coelacanths," he said. "This family represents a transition between the two large groups of youngest living coelacanths from the fossil record, Mawsoniidae and Latimeriidae."
Diplurid coelacanths are typically smaller than the two families with which they are most closely associated, Mawsoniidae and Latimeriidae. Mawsoniidae and Latimeriidae both have late Cretaceous members reaching large body sizes, ranging from 1 meter to 3 meters in total body length, Graf said.
Reidus hilli provides clues to missing coelacanth history Reidus hilli is named, in part, for the amateur collector who discovered the fish, Robert R. Reid.
A Fort Worth resident, Reid has collected fossils for decades. He found the fossil specimen while walking some land that had been prepared for construction of new homes. Reid noticed the fossil lying loose on the ground in a washed out gully created by run-off.
Following Graf's analysis, Reid was surprised to learn he'd collected a coelacanth -- and a new species.
"When I found it, I could tell it was a bone but I didn't think it was anything special," said Reid, recalling the discovery. "I certainly didn't think it was a coelacanth."
At the time, SMU paleontologist Louis L. Jacobs recommended to Reid that he donate the fossil and have it scientifically identified. Reid gave the fossil to SMU's Shuler Museum of Paleontology in the Roy M. Huffington Department of Earth Sciences.
"It is astounding what can be learned from the discoveries that people like Rob Reid make in their own backyards," said Jacobs, an SMU professor of earth sciences and president of SMU's Institute for the Study of Earth and Man. "The discovery of living coelacanths in the Indian Ocean after being presumed extinct for 70 million years highlights one of the great mysteries of ocean life. Where were they all that time? The new fossil from Texas is a step toward understanding this fascinating history."
Reidus hilli is the latest of many fossils Reid has discovered. Others also have been named for him.
Reidus hilli discovered in Duck Creek Formation of North Texas
Reidus hilli came from the fossil-rich Duck Creek Formation, which is a layer-cake band of limestone and shale about 40 feet thick.
The fossil was found in marine sediments, Graf said. It is one of many marine fossils found in the North Texas area, which 100 million years ago was covered by the Western Interior Seaway that divided North America from the Gulf of Mexico to the Arctic Ocean.
"That is unique to younger coelacanths," Graf said. "The oldest coelacanths were usually found in freshwater deposits and it wasn't until the Cretaceous that we start seeing this transition into a more marine environment."
Fossil also named for Robert T. Hill, "Father of Texas Geology"
Graf also named the fossil for Robert T. Hill, a geologist with the U.S. Geological Survey who led surveys of Texas during the 1800s. Hill described much of the geology of Texas, including the Duck Creek Formation. Hill is acclaimed as the "Father of Texas Geology."
Identification of Reidus hilli brings the number of coelacanth species worldwide to 81, including two that are alive today. Sources report that 229 living coelacanths have been caught since 1938.

Story Source:
The above story is reprinted from materials provided by Southern Methodist University. The original article was written by Margaret Allen.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:
  1. John Graf. A new Early Cretaceous coelacanth from Texas. Historical Biology: An International Journal of Paleobiology, Volume 24, Issue 4, 2012 DOI: 10.1080/08912963.2012.696636

Monday, October 15, 2012

Chinese scientist says prehistoric man ate pandas.

China's beloved national symbol—the panda—may have been seen quite differently by ancient humans: as food.
Scientist Wei Guangbiao says prehistoric man ate pandas in an area that is now part of the city of Chongqing in southwest China. Wei, head of the Institute of Three Gorges Paleoanthropology at a Chongqing museum, says many excavated panda fossils "showed that pandas were once slashed to death by man." The Chongqing Morning Post quoted him Friday as saying: "In primitive times, people wouldn't kill animals that were useless to them" and therefore the pandas must have been used as food. But he says pandas were much smaller then. Wei says wild pandas lived in Chongqing's high mountains 10,000 to 1 million years ago. The Chinese government invests greatly in studying the native species and trying to ensure its survival. Pandas number about 1,600 in the wild, where they are critically endangered due to poaching and development. More than 300 live in captivity, mostly in China's breeding programs.

Tuesday, February 28, 2012

New Fossil Penguin from New Zealand May Be the Biggest Ever.

Two Kairuku penguins come ashore, passing a stranded Waipatia dolphin. (Credit: Artwork by Chris Gaskin, owner and copyright owner: Geology Museum, University of Otago. Used with permission.)
Source: Science Daily
ScienceDaily (Feb. 27, 2012) — After 35 years, a giant fossil penguin has finally been completely reconstructed, giving researchers new insights into prehistoric penguin diversity.
The bones were collected in 1977 by Dr. Ewan Fordyce, a paleontologist from the University of Otago, New Zealand. In 2009 and 2011, Dr. Dan Ksepka, North Carolina State University research assistant professor of marine, earth and atmospheric sciences and North Carolina Museum of Natural Sciences colleague Dr. Paul Brinkman traveled to New Zealand to aid in the reconstruction of the giant penguin fossil.
Researchers dubbed the penguin Kairuku, a Maori word that loosely translates to "diver who returns with food." Ksepka was interested in the fossil because its body shape is different from any previously known penguin, living or extinct. He was also interested in the diversity of penguin species that lived in what is now New Zealand during the Oligocene period, approximately 25 million years ago.
According to Ksepka, "The location was great for penguins in terms of both food and safety. Most of New Zealand was underwater at that time, leaving isolated, rocky land masses that kept the penguins safe from potential predators and provided them with a plentiful food supply."
Kairuku was one of at least five different species of penguin that lived in New Zealand during the same period. The diversity of species is part of what made the reconstruction difficult, and the penguin's unique physique added to the difficulty.
"Kairuku was an elegant bird by penguin standards, with a slender body and long flippers, but short, thick legs and feet," says Ksepka. "If we had done a reconstruction by extrapolating from the length of its flippers, it would have stood over 6 feet tall. In reality, Kairuku was around 4-feet-2 inches tall or so."
The researchers reconstructed Kairuku from two separate fossils, using the skeleton of an existing king penguin as a model. The result is a tall bird with an elongated beak and long flippers -- easily the largest of the five species that were common to the area in that time period.
New Zealand has a history of producing exceptional fossils that give important insights into the history of penguins and other marine creatures. Ksepka hopes that the reconstruction of Kairuku will give other paleontologists more information about some the other fossils found in that area as well as add to the knowledge about giant penguin species. "This species gives us a more complete picture of these giant penguins generally, and may help us to determine how great their range was during the Oligocene period."
Ksepka's research was funded by a grant from the National Science Foundation and support from the University of Otago. Ksepka has a research appointment at the North Carolina Museum of Natural Sciences. The Department of Marine, Earth and Atmospheric Sciences is part of the College of Physical and Mathematical Sciences.