Smithsonian Science » paleontology

Giant prehistoric turtle from Colombia chomped everything in sight–including crocodiles!

John Barrat — Thu, 17 May 2012 17:39:39 +0000

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, the Smithsonian Tropical Research Institute and the Florida Museum of Natural History have just described such a specimen from the fossilized remains of this 60-million-year-old South American giant that lived in what is now Colombia.

Image right: Artist’s conception of Carbonemys eating a small crocodylomorph (Artwork by Liz Bradford)

The 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.

Cadena; Dan Ksepka, N.C. State paleontologist and research associate at the North Carolina Museum of Natural Sciences; paleontologist Carlos Jaramillo of the Smithsonian Tropical Research Institute in Panama, and paleontologist Jonathan Bloch of the Florida Museum of Natural History are co-authors of the scientific description of the turtle which appears in the Journal of Systematic Paleontology.

Image left: Edwin Cadena, the scientist who discovered the fossil of Carbonemys, poses next to its reconstructed fossil shell. (Photo courtesy Dan Ksepka, NC State University)

“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. Palentologist Ksepka 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,” he says. “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.”–Source: NC State University

First ever record of insect pollination captured in 100 million-year-old amber

John Barrat — Tue, 15 May 2012 13:24:47 +0000

Amber from Cretaceous deposits (110-105 million years ago) in Northern Spain has revealed the first-ever record of insect pollination. Scientists have discovered several specimens of tiny insects covered with pollen grains in two pieces of amber, revealing the first record of pollen transport and social behavior in this group of animals. The results are published in the Proceedings of the National Academy of the Science (PNAS) dated 14-18 May 2012.

Image right: Gymnosperm pollen attached to the abdomen and wing of a thysanopteran from the Alava amber (Credit: Enrique Peñalver, IGME).

The international team of scientists comprises: Enrique Peñalver and Eduardo Barrón from the Instituto Geológico y Minero de España in Madrid; Xavier Delclòs from the University of Barcelona; Andre and Patricia Nel from the Muséum national d’histoire naturelle in Paris; Conrad Labandeira from the Smithsonian’s National Museum of Natural History in Washington D.C.; and Carmen Soriano and Paul Tafforeau from the European Synchrotron Radiation Facility in Grenoble, France. The amber samples were from the collection of the Museo de Ciencias Naturales de Álava in Spain.

Today, more than 80 percent of plant species rely on insects to transport pollen from male to female flower parts. Pollination is best known in flowering plants but also exists in so-called gymnosperms, seed-producing plants like conifers. Although the most popular group of pollinator insects are bees and butterflies, a myriad of lesser-known species of flies, beetles or thrips have co-evolved with plants, transporting pollen and in return for this effort being rewarded with food.

Image left: An artist’s conception of of Gymnospollisthrips with pollen attached to the body over an ovulate organ of a gingko (Credit: Enrique Peñalver, IGME).

During the last 20 years, amber from the Lower Cretaceous found in the Basque country in Northern Spain has revealed many new plant and animal species, mainly insects. Here, the amber featured inclusions of thysanopterans, so-called thrips, a group of minute insects of less than 2 millimeters long that feed on pollen and other plant tissues. They are efficient pollinators for several species of flowering plants.

Two amber pieces revealed six fossilized specimens of female thrips with hundreds of pollen grains attached to their bodies. These insects exhibit highly specialized hairs with a ringed structure to increase their ability to collect pollen grains, very similar to the ones of well known pollinators like domestic bees. The scientists describe these six specimens in a new genus (Gymnopollisthrips) comprising two new species, G. minor and G. major.

The most representative specimen was also studied with synchrotron X-ray tomography at the European Synchrotron Radiation Facility to reveal the pollen grain distribution over the insect’s body in 3D and at very high resolution. The pollen grains are very small and exhibit the adherent features needed so that insects can transport them. The scientists conclude that this pollen is from a kind of cycad or ginkgo tree, a kind of living fossil of which only a few species are known to science. Ginkgos are either male or female, and male trees produce small pollen cones whereas female trees bear ovules at the end of stalks which develop into seeds after pollination.

Image right: Synchrotron tomography image of Gymnospollisthrips minor showing pollen. (Credit: ESRF).

Why did these tiny insects collect and transport gingko pollen 100 million years ago? Their ringed hairs cannot have grown due to an evolutionary selection benefiting the trees. The benefit for the thrips can only be explained by the possibility their larvae ate pollen. This suggests that this species formed colonies with larvae living in the ovules of some kind of gingko for shelter and protection, and female insects transporting pollen from the male gingko cones to the female ovules to feed the larvae and at the same time pollinate the trees.

More than one hundred million years ago, flowering plants started to diversify enormously, eventually replacing conifers as the dominant species. “This is the oldest direct evidence for pollination, and the only one from the age of the dinosaurs,” says Carmen Soriano, who led the investigation of the amber pieces with X-ray tomography at the ESRF. “The co-evolution of flowering plants and insects, thanks to pollination, is a great evolutionary success story. It began about 100 million years ago, when this piece of amber fossil was produced by resin dropping from a tree, which today is the oldest fossil record of pollinating insects. Thrips might indeed turn out to be one of the first pollinator groups in geological history, long before evolution turned some of them into flower pollinators.” –Source: European Synchrotron Radiation Facility

$35-million donation will build new dinosaur hall at National Museum of Natural History

John Barrat — Thu, 03 May 2012 16:58:22 +0000

The National Museum of Natural History announced today that it will construct a new dinosaur exhibition hall made possible by a $35 million donation from David H. Koch, executive vice president of Koch Industries and philanthropist. This renovation—the largest and most complex in the museum’s history—offers an opportunity to showcase the museum’s unrivaled collection of 46 million fossils and present the most up-to-date scientific research possible in the exhibition. Design preparations for the renovation will begin immediately.

The existing dinosaur hall will remain open until spring 2014, when it will be closed to the public to allow construction to begin; selected dinosaur specimens will remain on view in other public areas of the museum.

Image right and below: The Dinosaur Hall at the Smithsonian’s National Museum of Natural History.

The Smithsonian Board of Regents approved the naming of the 25,000-square-foot exhibition space April 30 in recognition of Koch’s gift—$35 million of the exhibition’s total estimated cost of $45 million. This is the largest single gift in the history of the Natural History Museum. Koch has contributed to many cultural, educational and health organizations, including Lincoln Center, the Metropolitan Museum of Art, American Museum of Natural History and Massachusetts Institute of Technology. Koch has been a member of the National Museum of Natural History’s board for five years and provided the lead gift for the David H. Koch Hall of Human Origins, which opened in 2010.

“Dinosaurs have always been one of the Smithsonian’s most important and popular exhibitions,” said Cristián Samper, director of the National Museum of Natural History. “The new paleobiology and dinosaur hall will enable us not only to show remarkable fossils, but also to present the latest scientific findings about how life on Earth has evolved.”

“We are grateful to David Koch for this gift that will allow the Smithsonian to update one of the most important and popular exhibitions in the Smithsonian’s National Museum of Natural History,” said Secretary of the Smithsonian Wayne Clough. “Millions of Americans and visitors from all over the world will learn and be inspired for years to come.”

The current dinosaur hall began as “The Hall of Extinct Monsters” when the museum opened in 1910. The museum’s most recent public display of dinosaurs and paleontology has been essentially unchanged for more than 30 years. Although the museum has one of the most comprehensive collections of fossils and a staff of eminent paleobiologists, the exhibition has become outdated because the museum lacked the funding for a total renovation of the space. With this gift, the museum can begin work on a complete overhaul of the exhibition, which has always been a “must-see” destination for families and students visiting the Smithsonian. The new hall will present the fossil record in fresh, new ways to show how dinosaurs and other extinct creatures lived in changing environments.

Renovation of the new hall requires extensive infrastructure work, which will be paid for with federal funds. Crews will later disassemble and conserve the enormous specimens in the exhibit spaces. It is estimated that more than 10,000 bones and other fragile specimens will be removed from the current exhibition before construction begins.

The National Museum of Natural History has an annual federal budget of $68 million in FY 2012, with a professional staff of more than 460 employees. The museum houses 127 million specimens and artifacts—the largest collection at the Smithsonian—and hosts an average of 7 million visitors a year. Its scientists publish approximately 500 scientific research papers every year. Recent renovations of major exhibitions in the museum include the Behring Family Hall of Mammals (2003), the Butterfly Pavilion (2007), the Sant Ocean Hall (2008) and the David H. Koch Hall of Human Origins (2010).

Meet the 125-million-year-old pollinator “Jeholopsyche liaoningensis”

John Barrat — Mon, 19 Mar 2012 18:45:23 +0000

What: Jeholopsyche liaoningensis is a new genus and species of flying insect from northeastern China, recently revealed in two new fossil specimens. Moderate in size, adults have a remarkably long, straw-like, ridged proboscis (or “tongue”) covered with well-developed, dense hairs that ended in a fleshy tip. Other characteristics included large separated eyes, long antennae and long wings.

When: J. liaoningensis lived some 125 million years ago alongside the dinosaurs just as flowering plants (angiosperms) were beginning to appear. This species has long been extinct. It is the first member of the Aneuretopsychidae, a prehistoric family of insects, to be discovered so exquisitely preserved that scientists can see and study the anatomical detail of its body parts, including the abdomen, antennae, thorax, forewings, legs and the head and mouthparts, especially the proboscis. This new specimen also reveals previously unknown ancient relationships between plants and these spectacular insects.

Image above: J. liaoningensis gen. et sp. n. Holotype, specimen CNU-M-LB-2005-002-2, counterpart. Image below: Close-up of the proboscis of J. liaoningensis accompanied by a scientific illustration of the proboscis as well. (Click photos to enlarge)

How: This insect lived by sucking nectar-like fluid from deep funnels or similar tubular structures that were part of the reproductive features of seed-producing plants such as certain conifer, cycad and ginkgo-like hosts, collectively known as gymnosperms. J. liaoningensis was one of a diverse guild of long-proboscis insects that fed upon these plants, including flies, lacewings and possibly moths. Scientists know that it “nectared” gymnosperms and not angiosperms because at that time the most primitive angiosperms did not have deep-throated, tubular flowers whereas some gymnosperm hosts did have reproductive structures that would accommodate the proboscis of J. liaoningensis.

Where: Discovered recently in China’s Yixian Formation, near Beipiao City of Liaoning Province, China. The Yixian Formation is a geological formation holding deposits that span several millions of years during the Early Cretaceous Period. It is well known for the abundant fossils of plants, animals, such as feathered dinosaurs, and insects that have been discovered there, broadly known as the Jehol Biota.

Image left: J. liaoningensis gen. et sp. n. Holotype, specimen CNU-M-LB-2005-002-1, part.

Who: These specimens were described and named in the journal Zookeys recently by Dong Ren and ChungKun Shih of the Capital Normal University, Beijing, and Conrad Labandeira of the Smithsonian’s National Museum of Natural History. Article link: “A well-preserved aneuretopsychid from the Jehol Biota of China (Insecta, Mecoptera, Aneuretopsychidae)”

New fossil whale species raises mystery regarding why narwhals and belugas live only in cold water

John Barrat — Wed, 07 Mar 2012 04:05:01 +0000

A newly described species of toothed whale that lived some 3-4 million years ago during the Pliocene, is causing scientists to reconsider what is known about its living cold-water relatives: narwhals and belugas. These living marine mammals, ancient fossils show, have not always been the cold-water adapted creatures they are today, and why and when they evolved to live only in northern latitudes remains a mystery.

Bohaskaia monodontoides, as the new fossil whale is known, was recently described in a paper in the Journal of Vertebrate Paleontology by Jorge Velez-Juarbe of Howard University, who is also a Smithsonian predoctoral fellow, and Nicholas Pyenson of the Smithsonian’s National Museum of Natural History. This new species is known only from a nearly complete skull found in 1969 in a mine near Hampton, Va. Since its discovery, the skull has been housed in the paleontology collections of the Smithsonian’s National Museum of Natural History. It was loosely identified as belonging to a beluga whale but it had never been closely studied.

Image right: An artist’s conception of Bohaskaia monodontoides, foreground. Behind and above are a beluga and narwhal. (Artwork by Carl Buell)

In 2010, Velez-Juarbe and Pyenson began a close anatomical comparison of the fossil skull with the skeletons of belugas and narwhals kept in the collections of the Division of Mammals at the museum. Their study confirmed that the fossil skull was that of a new toothed whale species, one that shared features of the snout and face with belugas and narwhals. The fossil skull contained enough unique features however, to merit its placement as a new genus and species.

“Fossils referred to as belugas have been known from fragmentary bits, but skulls are so revealing because they contain so many informative features,” Pyenson says. “We realized this skull was not something assignable to a beluga, and when we sat down, comparing the fossil side by side with the actual skulls of belugas and narwhals, we found it was a very different animal.”

Image left: From left to right: Jorge Velez-Juarbe holds the skull of beluga whale; Dave Bohaska holds the skull of Bohaskaia monodontoides; and Nick Pyenson with the skull and tusk of a narwhal. They are standing in the marine mammal collections area of the Smithsonian’s National Museum of Natural History. (Photo courtesy Jorge Velez-Juarbe)

As Bohaskaia monodontoides was found in the temperate climate of Virginia, and a second extinct beluga-related toothed whale, Denebola branchycephala is known from a fossil found in Baja California, Velez-Juarbe and Pyenson surmise that the cold-climate adaptations of narwhals and beluga, which today live and breed only in the Arctic and sub-arctic, must have evolved only recently.

Image right: The fossil skull of Bohaskaia monodontoides. (Photos courtesy of Jorge Velez-Juarbe’s blog site Caribbean Paleobiology)

“The fact is that living belugas and narwhals are found only in the Arctic and subarctic, yet the early fossil record of the monodontids extends well into temperate and tropical regions,” Pyenson says. “For evidence of how and when the Arctic adaptations of belugas and narwhals arose we will have to look more recently in time.”

The change may be “related to oceanographic changes during or after the Pliocene affecting the marine food chain,” Velez-Juarbe says, “then competition or dietary preferences drove monodontids further north.”

(Bohaskaia monodontoides, was named in honor of David J. Bohaska, a museum specialist in the Department of Paleobiology at the Smithsonian’s National Museum of Natural History.)

Link to Dr. Nicholas Pyenson’s blog: http://nmnh.typepad.com/pyenson_lab/

Largest snake the world has ever seen is being brought back to life by Smithsonian Channel

John Barrat — Tue, 06 Mar 2012 12:58:31 +0000

Slithering in at 48 feet long and weighing an estimated one-and-a-half tons, the largest snake the world has ever seen is being brought back to life. Sixty million years ago, in the mysterious era after the mass extinction of the dinosaurs, scientists believe that a colossal snake related to modern boa constrictors ruled a lost world. With exclusive access to what one scientist called “a once-in-a-lifetime discovery,” Smithsonian Channel(TM) will tell the extraordinary true story in TITANOBOA: MONSTER SNAKE, a two-hour special premiering Sunday, April 1 at 8 p.m. ET/PT.

The startling discovery of Titanoboa was made by a team of scientists working in one of the world’s largest open-pit coal mines at Cerrejon in La Guajira, Colombia. It is a snake that dwarfs the largest anaconda found today, and it has the size and character to challenge T-Rex in the public’s imagination.

The story behind this significant scientific revelation began in 2002, when a Colombian student visiting the coal mine made an intriguing discovery: a fossilized leaf that hinted at an ancient rainforest from the Paleocene epoch. Over the following decade, collecting expeditions led by the Smithsonian Tropical Research Institute and the Florida Museum of Natural History, University of Florida opened a unique window into perhaps the first rainforest on Earth. Fossil finds included giant turtles and crocodiles, as well as the first known bean plants and some of the earliest banana, avocado and chocolate plants. But their most spectacular discovery was the fossilized vertebrae of a previously undiscovered species of snake, one so large it defied imagination.

Together with their research teams, Jonathan Bloch of the Florida Museum of Natural History, University of Florida and Carlos Jaramillo of the Smithsonian Tropical Research Institute, joined forces with one of the world’s foremost experts in ancient snakes, Jason Head of the University of Nebraska, to unlock the mysteries of this ancient time and discover exactly how Titanoboa appeared, lived and hunted. The fossilized remains revealed that, after the extinction of the dinosaurs, the tropics were warmer than today and witnessed the birth of the South American rainforest, in which huge creatures battled it out to become the planet’s top predators. Dominating this era was Titanoboa, the undisputed largest snake in the history of the world.

Most of the fossil record of ancient snakes is comprised of vertebrae like the one that launched the Titanoboa investigation. Snake skulls are almost never found as they are extremely fragile and usually disintegrate – making it almost impossible to create a full and accurate picture of these extinct creatures. But during the filming of TITANOBOA: MONSTER SNAKE, the scientists managed to uncover not just one, but fragments of three skulls, allowing them to derive for the first time what this ancient giant looked like.

A scientifically accurate, life-sized replica of Titanoboa appears in the film and will go on display for the first time at the National Museum of Natural History beginning March 30, 2012. The exhibition will travel to museums across the country beginning in fall 2013. Titanoboa: Monster Snake is a collaboration between the Florida Museum of Natural History at the University of Florida in Gainesville, the University of Nebraska-Lincoln, and the Smithsonian Tropical Research Tropical Research Institute, and is circulated by the Smithsonian Institution Traveling Exhibition Service.

The two-hour special explores how this monster snake would have lived by visiting its living cousins, boa constrictors and anacondas, in the Florida Everglades and the Venezuelan Grasslands. The scientists’ research yields some intriguing and terrifying insights, including the climate in which it lived and size of the snake. All of these clues come together to paint a picture of Titanoboa’s world, which is brought back to life in stunning CGI. Here we see how the colossal snake ruled as an ancient apex predator among a land of tropical mega-beasts.

TITANOBOA: MONSTER SNAKE follows the scientific sleuths back to the mine, into the labs, and on an expedition to understand modern giant constrictors. It creates a picture of the then largest predator on the planet – a creature that until now has only populated fiction and nightmares, but can finally be displayed as a marvel of nature.

Two new species of extinct camels discovered in Panama Canal excavations

John Barrat — Wed, 29 Feb 2012 14:25:21 +0000

The discovery of two new extinct camel species by scientists from the University of Florida and the Smithsonian is casting new light on the history of the tropics, a region containing more than half the world’s biodiversity and some of its most important ecosystems.

Image above: University of Florida doctoral student Aldo Rincon holds the lower jaw of Aguascalietia panamaensis, a newly described species of ancient camel. The 20-million-year-old specimen was recovered from the Las Cascadas formation in Panama. (Photos by Jeff Gage, University of Florida)

Appearing online this week in the Journal of Vertebrate Paleontology, the study is the first published description of a fossil mammal discovered as part of an international project in Panama. Funded with a grant from the National Science Foundation, University of Florida paleontologists and geologists are working with the Panama Canal Authority and scientists at the Smithsonian Tropical Research Institute to make the most of a five-year window of excavations during Panama Canal expansions that began in 2009.

Florida Museum of Natural History photo by Jeff GageThe discovery extends the distribution of mammals to their southernmost point in the ancient tropics of Central America. The tropics contain some of the world’s most important ecosystems, including rain forests that regulate climate systems and serve as a vital source of food and medicine, yet little is known of their history because lush vegetation prevents paleontological excavations.

Image above: This lower jaw of Aguascalietia panamaensis, a new species of ancient camel, represents one of the oldest mammals from Panama. Recovered from the Las Cascadas formation, the 20-million-year-old specimen extends the geographic distribution of mammals to their southernmost point.

“We’re discovering this fabulous new diversity of animals that lived in Central America that we didn’t even know about before,” said co-author Bruce MacFadden, vertebrate paleontology curator at the Florida Museum on the University of Florida Campus. “The family originated about 30 million years ago and they’re found widespread throughout North America, but prior to this discovery, they were unknown south of Mexico.” Study co-authors are Catalina Suarez and Carlos Jaramillo of the Smithsonian Tropical Research Institute and Jonathan Bloch of the University of Florida.

Researchers described two species of ancient camels that are also the oldest mammals found in Panama: Aguascalietia panamaensis and Aguascalientia minuta. Distinguished from each other mainly by their size, the camels belong to an evolutionary branch of the camel family separate from the one that gave rise to modern camels based on different proportions of teeth and elongated jaws.

“Some descriptions say these are ‘crocodile-like’ camels because they have more elongated snouts than you would expect,” said lead author Aldo Rincon, a UF geology doctoral student. “They were probably browsers in the forests of the ancient tropics. We can say that because the crowns are really short.”

Rincon discovered the fossils in the Las Cascadas formation, unearthing pieces of a jaw belonging to the same animal over a span of two years, he said.

“When I came back to the museum, I started putting everything together and realized, ‘Oh wow, I have a nearly complete jaw,’ ” Rincon said.

The study shows that despite Central America’s close proximity to South America, there was no connection between continents because mammals in the area 20 million years ago all had North American origins. The Isthmus of Panama formed about 15 million years later and the fauna crossed to South America 2.5 to 3 million years ago, MacFadden said.

Camels belong to a group of even-toed ungulates that includes cattle, goats, sheep, deer, buffalo and pigs. Other fossil mammals discovered in Panama from the early Miocene have been restricted to those also found in North America at the time. While researchers are sure the ancient camels were herbivores that likely browsed in forests, they are still analyzing seeds and pollen to better understand the environment of the ancient tropics.

Researchers will continue excavating deposits from the Panama Canal during construction to widen and straighten the channel and build new locks, expected to continue through 2014. The project is funded by a $3.8 million NSF grant to develop partnerships between the U.S. and Panama and engage the next generation of scientists in paleontological and geological discoveries along the canal.–Source: University of Florida

How do paleontologists identify dinosaur teeth? Smithsonian Curator Matthew Carrano identifies Cretaceous dinosaur teeth from the Washington D.C. area.

John Barrat — Tue, 21 Feb 2012 14:05:48 +0000

Wayne Clough & Carlos Jaramillo, at a research site near the Panama Canal.

John Barrat — Thu, 16 Feb 2012 18:31:09 +0000

Smithsonian Secretary Wayne Clough, left, talks with Carlos Jaramillo, scientist at the Smithsonian Tropical Research Institute in Panama, at a research site near the Panama Canal. Jaramillo and his team are collecting and examining prehistoric fossils exposed during the recent widening of the Canal. To date, they have discovered the fossils of a 12-inch-tall horse, a tiny camel, huge rhinos, turtles and trees 17- to 23-million-years-old. They have also uncovered evidence indicating the Isthmus of Panama did not emerge three million years ago, but as early as 22 million years ago. (Photo by Johnny Gibbons)

190-million-year-old dinosaur nesting site discovered in South Africa

John Barrat — Fri, 27 Jan 2012 14:39:08 +0000

An excavation at a site in South Africa has unearthed the 190-million-year-old dinosaur nesting site of the prosauropod dinosaur Massospondylus–revealing significant clues about the evolution of complex reproductive behavior in early dinosaurs.

Image right: The hand print of a baby dinosaur from the nesting site in South Africa. (Images courtesy University of the Witwatersrand)

A new study, entitled Oldest known dinosaur nesting site and reproductive biology of the Early Jurassic sauropodomorph Massospondylus and published in the international journal Proceedings of the National Academy of Sciences, was led by Canadian palaeontologist Robert Reisz, a professor of biology at the University of Toronto at Mississauga, and co-authored by Hans-Dieter Sues of the Smithsonian’s National Museum of Natural History; Eric Roberts of James Cook University, Australia; and Adam Yates of the Bernard Price Institute for Paleontological Research.

The study reveals clutches of eggs, many with embryos, as well as tiny dinosaur footprints, providing the oldest known evidence that the hatchlings remained at the nesting site long enough to at least double in size.

The authors say the newly unearthed dinosaur nesting ground is more than 100 million years older than previously known nesting sites.

Image left: A fossil from the nesting site showing seven eggs, some with the embryos exposed.

At least 10 nests have been discovered at several levels at this site, each with up to 34 round eggs in tightly clustered clutches. The distribution of the nests in the sediments indicate that these early dinosaurs returned repeatedly (nesting site fidelity) to this site, and likely assembled in groups (colonial nesting) to lay their eggs, the oldest known evidence of such behavior in the fossil record.

The large size of the mother, at six meters in length, the small size of the eggs, about six to seven centimetrs in diameter, and the highly organized nature of the nest, suggest that the mother may have arranged them carefully after she laid them.

“The eggs, embryos, and nests come from the rocks of a nearly vertical road cut only 25 meters long,” Reisz says. “Even so, we found ten nests, suggesting that there are a lot more nests in the cliff, still covered by tons of rock. We predict that many more nests will be eroded out in time, as natural weathering processes continue.”

Image right: A nest of dinosaur eggs from the South African nesting site.

The fossils were found in sedimentary rocks from the Early Jurassic Period in the Golden Gate Highlands National Park in South Africa. This site has previously yielded the oldest known embryos belonging to Massospondylus, a relative of the giant, long-necked sauropods of the Jurassic and Cretaceous periods.

“This amazing series of 190 million year old nests gives us the first detailed look at dinosaur reproduction early in their evolutionary history, and documents the antiquity of nesting strategies that are only known much later in the dinosaur record,” says Evans.