Image right: Whale bone fossil showing the three tooth marks from a shark. Click photos to enlarge. (Photo by Stephen Godfrey)

Three tooth marks on the rib indicate the whale was once severely bitten by a strong-jawed animal. Judging by the 6 centimeter (2.4 inch) spacing between tooth marks, scientists believe the attacker was a mega toothed shark Carcharocles megalodon, or perhaps another species of large shark which was alive at that time. The whale appears to have been an ancestor of a great blue or humpback.

“One certainly doesn’t expect to find evidence of animal behavior preserved in the fossil record, but this fossil shows just that, a failed predation,” explains Stephen Godfrey, paleontologist at the Calvert Marine Museum in Solomons, Md. and a Smithsonian research collaborator, who discovered the fossil. “The shark may have gone away with a mouthful, but it didn’t kill the whale”

Image left: This illustration shows one plausible way, and the most likely, in which the three calluses preserved on the whale rib came about: a bite from one of the large Pliocene sharks with which these huge baleen whales had to contend. (Illustration by Timothy Scheirer © CMM; used with permission)

Scientists know the whale survived because “most of the fossil fragment is covered with a type of bone known as woven bone, which forms rapidly in response to localized infection,” explains Don Ortner, an anthropologist at the Smithsonian’s National Museum of Natural History and authority on the effect of disorders on skeletal tissue. “Biomechanically woven bone is not very strong. The body eventually remodels it into compact bone, but it takes time.” CT scans reveal evidence of inflammation in the bone marrow consistent with infection.

The presence of the woven bone indicates the healing was incomplete and the whale died, the scientists estimate, between two and 6 weeks after the attack. The whale’s death may have been unrelated to its infection and injury, Ortner says.  “We don’t know why it died.”

Based on the curvature of the shark’s jaw, as indicated by the arc of the impressions of its teeth, the scientists believe the shark was relatively small, between 4- and 8-meters (13-20 feet) long.

In the realm of paleontology, “only a handful of fossils show these kinds of interactions,” Godfrey explains. “There are lots of bite marks on fossils showing where the animal died and its carcass was scavenged. This fossil is one of a very few examples that shows a trauma clearly attributed to another animal, yet also shows the victim survived the event.”

“Bone Reactions on a Pliocene Cetacean Rib Indicate Short-Term Survival of Predation Event” was published in the International Journal of Osteoarchaeology and is co-authored by Robert Kallal and Stephen Godfrey of the Calvert Marine Museum in Solomons, Md., and Donald Ortner of the Smithsonian’s National Museum of Natural History.

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This illustration by Carl Buell depicts Ocucajea picklingi (center) and Supayacetus muizoni (bottom), two ancient whales that lived off the Peruvian coast during the Eocene, between 56-34 million years ago.  At top is an unnamed whale and the fossil penguin Perudyptes devriesi. Nicholas Pyenson, paleobiologist at the Smithsonian’s National Museum of Natural History, helped discover fossils of these whales in Peru’s Pisco Basin. Read his account of the discovery on this Ocean Portal blog post.

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The hatchling nodosaur fossil was donated to the Smithsonian’s National Museum of Natural History by Stanford, where it is on display to the public and also available for research.

After finding the fossil Stanford identified it as a nodosaur and called David Weishampel, a professor of anatomy at Johns Hopkins and a paleontologist and expert in dinosaur systematics. Weishampel and his colleagues established the fossil’s identity as a nodosaur by identifying a distinctive pattern of bumps and grooves on the skull. The body in the tiny fossil was only 13 cm long, just shorter than the length of a dollar bill. Adult nodosaurs are estimated to have been 20 to 30 feet long.

They then did a computer analysis of the skull shape, comparing its proportions to those of ten skulls from different species of ankylosaurs, the group that contains nodosaurs. They found that this dinosaur was closely related to some of the nodosaur species, although it had a shorter snout overall than the others. Comparative measurements enabled them to designate a new species, Propanoplosaurus marylandicus. In addition to being the youngest nodosaur ever found, it is the first hatchling of any dinosaur species ever recovered in the eastern United States.  Source: Johns Hopkins Medicine

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In a new study  in the journal Palaeontology, University of Florida and Smithsonian Tropical Research Institute scientists describe a new 20-foot extinct species discovered in the same Colombian coal mine with Titanoboa, the world’s largest snake. The findings help scientists better understand the diversity of animals that occupied the oldest known rainforest ecosystem, which had higher temperatures than today, and could be useful for understanding the impacts of a warmer climate in the future.

Image right: This illustration shows how Acherontisuchus guajiraensis, a 60-million-year-old ancestor of crocodiles, would have looked in its natural setting. Titanoboa, the world’s largest snake, is pictured in the background. (Illustration by Danielle Byerley/click to enlarge)

The 60-million-year-old freshwater relative to modern crocodiles is the first known land animal from the Paleocene New World tropics specialized for eating fish, meaning it competed with Titanoboa for food. But the giant snake could have consumed its competition, too, researchers say.

“The younger individuals were definitely not safe from Titanoboa, but the biggest of these species would have been a bit much for the 42-foot snake to handle,” said lead author Alex Hastings, a graduate student at the Florida Museum of Natural History and UF’s department of geological sciences.

Image left: University of Florida researchers unearth fossils from the 60-million-year-old Cerrejon formation in northeastern Colombia, one of the world’s largest open-pit coal mines. (Photo by Edwin Cadena)

The new species is a dyrosaurid, commonly believed to be primarily ocean-dwelling, coastal reptiles. The new adult specimens challenge previous theories the animals only would have entered freshwater environments as babies before returning to sea.

Fossils of a partial skeleton of the species, Acherontisuchus guajiraensis, show dyrosaurids were key players in northeastern Colombia and that diversity within the family evolved with environmental changes, such as an asteroid impact or the appearance of competitors from other groups, said Christopher Brochu, an associate professor of vertebrate paleontology in the department of geoscience at the University of Iowa, who was not involved in the study.

“We’re facing some serious ecological changes now,” Brochu said. “A lot of them have to do with climate and if we want to understand how living things are going to respond to changes in climate, we need to understand how they responded in the past. This really is a wonderful group for that because they managed to survive some catastrophes, but they seemed not to survive others and their diversity does seem to change along with these ecological signals.”

Image left: This photograph shows the size difference in the jawbones of two 60-million-year-old crocodile ancestors found in northeastern Colombia by University of Florida researchers.The newly described Acherontisuchus guajiraensis, top, and Cerrejonisuchus improcerus, bottom. C. improcerus was the first ancient crocodyliform found in the Cerrejon open-pit coal mine. The new species is the first known land animal from the Paleocene New World tropics specialized for eating fish. (Photo by Kristen Grace)

The species is the second ancient crocodyliform found in the Cerrejon mine of northern Colombia, one of the world’s largest open-pit coal mines. The excavations were led by study co-authors Jonathan Bloch, Florida Museum associate curator of vertebrate paleontology, and paleobotanist Carlos Jaramillo of the Smithsonian Tropical Research Institute.

“This one is related to a group that typically had these long snouts” Hastings said. “It would have had a relatively similar diet to the other (coastal) species, but surprisingly it lived in a more freshwater environment.”

The genus is named for the river Acheron from Greek mythology, “the river of woe,” since the animal lived in a wide river that emptied into the Caribbean. Unlike the first crocodile relative found in the area, which had a more generalized diet, the snout of the new species was long, narrow and full of pointed teeth, showing a specialization for hunting the lungfish and relatives of bonefish that inhabited the water.

“The general common wisdom was that ancestrally all crocodyliforms looked like a modern alligator, that all of these strange forms descended from a more generalized ancestor, but these guys are showing that sometimes one kind of specialized animal evolved from a very different specialized animal, not a generalized one,” Brochu said. “It’s really showing us a level of complexity to the history that 10 years ago was not anticipated.”

During the Paleocene in South America, the environment was dominated by reptiles, including giant snakes, turtles and crocodiles. The dyrosaurid family originated in Africa about 75 million years ago, toward the end of the age of dinosaurs, and arrived in South America by swimming across the Atlantic Ocean.

“The same thing that snuffed out the dinosaurs killed off most of the crocodiles alive at the time,” Hastings said. “The dyrosaurids are one of the few groups to survive the extinction and later become more successful.”

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Palms are recognized as icons of the tropics, in addition to being the source of many economically significant products that extend relevance of the group to millions of people daily. Striking morphological and ecological variability characterize this family of about 183 genera and more than 2,400 species and has inspired almost two centuries of botanical research.

Hidden from view, but no less compelling, is the internal structure of palms—an understanding of which is essential for interpreting many of the unique biological aspects of the family and discerning relationships among palm genera. The Anatomy of Palms (Oxford University Press; 2011), a new book by P. Barry Tomlinson, James W. Horn (Department of Botany, Smithsonian), and Jack B. Fisher is a definitive reference showcasing both the science and art inside palms.

The chief appeal of The Anatomy of Palms is some 800 color photographs that document the extent of palm anatomical diversity. To give the preparations a more natural, hydrated appearance, as well as to overcome technical difficulties inherent in making microscope slides of palm tissues, many of the photos were custom-made for the book.

Image left: Colpothrinax wrightii, the Cuban belly palm. Leaf lamina in transverse section, stained with aqueous toluidine blue. From The Anatomy of Palms.

Palm biologists, plant anatomists, and curious botanists working in other disciplines will find that the book contains abundant new data, new interpretations, and new ideas for future studies. The first section provides an overview of the diversity of vegetative structure in palms and an evolutionary analysis of anatomical characters across the entire family. The second section focuses on the systematic anatomy of palms and is a synthesis of anatomical observations in the context of the most recent classification of the family.

The Anatomy of Palms has the potential for initiating a new wave of reinterpretation of palm fossils because of their often excellent anatomical preservation. The book also gives the classical field of comparative anatomy a fresh perspective, which will hopefully inspire others to do similar work. (Adapted from an article in The Plant Press, Department of Botany, Smithsonian Institution)

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Meet Sahelanthropus tchadensis. This newly unveiled recreation by artist John Gurche is on view in the David H. Koch Hall of Human Origins at the Smithsonian’s National Museum of Natural History.

(Click image to enlarge)

Sahelanthropus tchadensis is one of the oldest known species on the human family tree and lived between 7 and 6 million years ago in West-Central Africa (Chad). Walking upright may have helped this species survive in diverse habitats—including forests and grasslands.  Although anthropologists have only cranial material from Sahelanthropus, studies so far indicate this early human had a combination of apelike and humanlike features. Their apelike features included a small brain (even slightly smaller than a chimpanzee’s!) sloping face, very prominent brow ridges, and elongated skull. Their humanlike features included small canine teeth, a short middle part of the face, and a spinal cord opening beneath the skull instead of towards the back, like in nonbipedal primates (or apes). For more information on Sahelanthropus tchadensis click this link to the Hall of Human Origins.

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But a new census of all dinosaur skeletons unearthed over a large area of Eastern Montana shows that Tyrannosaurus was too numerous to have subsisted solely on the dinosaurs it tracked and killed with its scythe-like teeth.

Image right: The cast of a Tyrannosaurus rex on display in UC Berkeley’s Valley Life Sciences Building. The original fossil skeleton from Montana’s Hell Creek Formation is in the Museum of the Rockies in Bozeman, Mont. (Randy Irmis)

Instead, argue paleontologists John “Jack” Horner from the Museum of the Rockies and Mark B. Goodwin from the University of California, Berkeley, T. rex was probably an opportunistic predator, like the hyena in Africa today, subsisting on both carrion and fresh-killed prey and exploiting a variety of animals, not just large grazers.
“In our census, T. rex came out very high, equivalent in numbers to Edmontosaurus, which many people had thought was its primary prey,” says Horner, curator of paleontology at the Museum of the Rockies in Bozeman, Mont., and Regents Professor at Montana State University. “This says that T. rex is not a cheetah, it’s not a lion. It’s more like a hyena.”

Map: The new dinosaur census covers a large area around Fort Peck Lake in Montana, where the Hell Creek Formation deposits are exposed over about 1,000 square kilometers.

“This putative apex predator is as abundant in the upper layers of the Hell Creek Formation as the herbivores, its reputed primary food source,” adds Goodwin, a curator in UC Berkeley’s Museum of Paleontology and assistant director of the museum. “And it’s even more plentiful in the other two-thirds of the formation. This supports the view that T. rex benefited from a much wider variety of food sources than live prey.”

The dinosaur census in the Hell Creek Formation of Montana, which dates from 65-95 million years ago, was begun in 1999 by Horner and Goodwin with the financial and occasional field support of Nathan Myhrvold, former chief technology officer for Microsoft Corp. The results, authored by Horner, Goodwin and Myhrvold, were published Feb. 9 in the open-access journal PLoS ONE.

Normally, Goodwin said, top predators are one-third or one-fourth as abundant as their prey, because of the larger energy needs of carnivores. Opportunistic hunters like the hyena, however, can be twice as abundant as the top predators. Horner suggests that juvenile and young adult T. rex may have been primarily flesh eaters, while the older adults, which developed proportionally larger, bone-crushing teeth as they aged, also consumed the bones and marrow of their prey.

The work was supported by donations from James Kinsey, Catherine B. Reynolds and Homer Hickam, as well as Intellectual Ventures, the Windway Foundation, the Smithsonian Institution and the University of California Museum of Paleontology.—Robert Sanders, University of California, Berkeley

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Paleontologists at Yale University and the Smithsonian Institution have discovered that Xenicibis, a member of the ibis family that lived about ten thousand years ago and was found only in Jamaica, most likely used its specialized wings like a flail, swinging its upper arm and striking its enemies with its thick hand bones.

Image right: Skeletal reconstruction of Xenicibis xympithecus based on a specimen at the Smithsonian’s National Museum of Natural History and fossils from the Red Hills Fissure cave deposits, Saint Andrews Parish, Jamaica. (Illustration by Nicholas Longrich, Yale University)

“No animal has ever evolved anything quite like this,” said Nicholas Longrich of Yale, who led the research. “We don’t know of any other species that uses its body like a flail. It’s the most specialized weaponry of any bird I’ve ever seen.”  Storrs Olson, ornithologist at the Smithsonian’s National Museum of Natural History, and Longrich are co-authors of a paper on this research published in the Proceedings of the Royal Society B.

As part of the new study, the researchers analyzed a number of recently discovered partial skeletons of Xenicibis and found that the wings were drastically different from anything they’d seen before. “When I first saw it, I assumed it was some sort of deformity,” Longrich said. “No one could believe it was actually that bizarre.”

Image left: The prehistoric Xenicibis used its wings like two clubs hinged at the wrist joint in order to swing at and attack one another. (Illustration by Nicholas Longrich, Yale University)

The bird, which was the size of a large chicken, is anatomically similar to other members of the ibis family except for its wings, which include thick, curved hand bones unlike those of any other known bird. Xenicibis also had a much larger breastbone and longer wings than most flightless birds. “That was our first clue that the wings were still being used for something,” Longrich said.

While other birds are known to punch or hammer one another with their wings, Xenicibis is the only known animal to have used its hands, hinged at the wrist joint, like two baseball bats to swing at and strike its opponents. Although modern day ibises do not strike one another in this fashion, they are very territorial, with mates often fighting other pairs over nesting and feeding rights.

It’s also possible that the birds used their club-like wings to defend themselves against other species that might have preyed on the birds’ eggs or young. Xenicibis is unusual in that it became flightless even in the midst of a number of predators, including the Jamaican yellow boa, a small extinct monkey and over a dozen birds of prey.

The team found that two of the wing bones in the collection showed evidence of combat, including a fractured hand bone and a centimeter-thick upper arm bone that was broken in half. The damage is proof of the extreme force the birds were able to wield with their specialized wings, Longrich said. –Suzanne Taylor Muzzin, Yale University Office of Public Affairs and Communications

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