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James Rossie

James Rossie conducting field work at Lake Turkana. Photo by Susanne Cote

By Daniel Dunaief

Dead men might not tell tales but fossilized apes and the soil around them may change a narrative. That’s what happened recently when a large collaboration of researchers gathered clues from an ape fossil in Moroto, Uganda that lived 21 million years ago and from a detailed analysis of the soil.

James Rossie in his lab. Photo by Emily Goble


Scientists have long thought apes started climbing upright, which is an important evolutionary step, all those years ago to reach fruit in a habitat dense with trees. Recent evidence from two publications in the journal Science, however, suggest that the habitat included grassland and woodlands.

James Rossie, Associate Professor in the Department of Anthropology at Stony Brook University, studied the teeth of the fossil, called Morotopithecus, to determine what this ancient ape ate.

“The important thing about the teeth of Morotopithecus is a shift towards folivory” or leaf eating, Rossie said. “The surface of the molars were elongated with well-developed crests” which indicate that this primate consumed leaves rather than fruit.

By contrast, molars of animals that eat fruit are more rounded. Additionally, carbon isotope dating of the enamel suggest that they fed on water-stressed plants. This discovery and analysis changes not only the narrative of this particular ape species, but also of the evolutionary progression and habitat of primates.

A rendering of ancient apes foraging in trees. Image courtesy of Corbin Rainbolt

This analysis indicated that apes lived in areas of open woodlands, where there were patches of trees separated by stretches of grassland about 10 million years earlier than scientists originally believed. During the miocene period, they would have had to evade predators such as Simbakubwa, an extinct carnivore that was larger than a lion.

“It was very unexpected that an ape with upright, versatile climbing abilities was living in a seasonal woodland with open, grassy patches, rather than in a closed tropical forest,” said Laura MacLatchy, a Professor in the Department of Anthropology at the University of Michigan and the leader on the study.

“The findings have transformed what we thought we knew about early apes, and the origins for where, when and why they navigate through the trees and on the ground in multiple different ways,” Robin Bernstein, Program Director for Biological Anthropology at the National Science Foundation, said in a statement. “The effort outlines a new framework for future studies regarding ape evolutionary origins.”

The fossils Rossie and his colleagues examined including the lower part of a face, the palate, upper teeth, a couple of vertebrae, the lower jaw, and a complete femur. It’s unclear if these fossils came from one individual or from a collection of apes. With considerable wear and tear on the teeth of the upper jaw, the owner of those bones was an adult, Rossie said.

The mandible of an ancient ape with the left molar enlargement inset. Photo by Laura MacLatchy

By studying the bones as puzzle pieces that fill in a narrative, researchers concluded that the smaller, thick femur, or thigh, bone helped the ape climb quickly and effectively up the trunks of trees.

The longer legs of a human push us away from trees, making it harder to climb, while the shorter, sturdy legs of an ape enable it to get closer to the trunk and reach lower branches quickly. 

Apes that fed on leaves would likely have had larger bodies to accommodate the need for a longer digestive tract. A heavier animal that navigated through trees would run the risk of falling to the ground if their weight caused a branch to break.

By climbing upright, apes could distribute their weight more evenly over several branches, enabling them to maneuver through the trees to the leaves while reducing the strain they put on any one branch.

In a second paper published together as a part of this analysis, soil researchers studied the environment at Moroto and at several other sites of similar age across eastern Africa.  These soil scientists determined that the early habitat included forests and grasslands.

Cooperative work

Rossie believes the work of numerous scientists over a long period of time not only represents a paradigm shift in thinking about ape evolution and the environment in Africa, but also in the way scientists across a wide range of expertise collaborate.

James Rossie conducting field work at Lake Turkana. Photo by Susanne Cote

The researchers who trained Rossie and his colleagues were more competitive and guarded, he said. They didn’t share information with each other about their findings and wanted other researchers to learn about their findings through journal publications.

“We decided to take a different strategy” about a dozen years ago, he said. “It occurred to us that these separate silo attempts to reconstruct these environments were incompatible, with different methods and strategies. We couldn’t put it together into a coherent picture.”

By working together with the same methods, the scientists had comparable data and developed a coherent picture. Such broad collaborations across a range of fields required a “bit of a leap of faith,” he added. The scientists knew and trusted each other.

Indeed, Rossie and MacLatchy have known each other since the early 2000s when MacLatchy first asked Rossie to study other fossils.

Bringing numerous researchers across a range of expertise was a “game theory experiment,” Rossie added. Researchers could have published smaller papers about each site more quickly, but chose to combine them into the more meaningful synthesis.

MacLatchy suggested that the work on this project that involved sharing data across multiple sites, as well as joining forces in a range of expertise, makes it possible to reconstruct habitats with much greater detail.

“We are also able to obtain a regional perspective, which is not possible if interpretations are based on individual fossil sites,” she said. “I’d like to think this kind of collaboration will become standard.”

A resident of Centerport, Rossie is a hockey fan and is pulling for the Islanders.

He enjoys studying teeth because a single tooth can provide considerable information about an animal’s place among other species and about its strategies for getting and processing food.

His professional studies have come full circle. As a college junior at St. Lawrence University, he attended a field school run by Harvard University and the National Museum of Kenya at Lake Turkana. Almost every moment of that experience made him more eager to pursue paleontology as a career.

“As fate would have it, my field project is now centered on an area on the west side of Lake Turkana that I first visited back in 1995,” he explained.

The Turkana Basin Institute serves as his home base during the field season and he is grateful for their ongoing logistical support.

As for future work, Rossie is studying the fossils of at least four different species of apes in Lake Turkana in Kenya.

By Daniel Dunaief

It’s not exactly a Rembrandt hidden in the basement until someone discovers it in a garage sale, but it’s pretty close.

More than two decades ago, a Malagasy graduate student named Augustin Rabarison spotted crocodile bones in northwestern Madagascar, so he and a colleague encased them in a plaster jacket for further study.

David Krause, who was then a Professor at Stony Brook University and is now the Senior Curator of Vertebrate Paleontology at the Denver Museum of Nature & Science, didn’t think the crocodile was particularly significant, so he didn’t open the jacket until three years later, in 2002.

When he unwrapped it, however, he immediately recognized a mammalian elbow joint further down in the encased block of rock. That elbow bone, as it turned out, was connected to a new species that is a singular evolutionary masterpiece that has taken close to 18 years to explore. 

Recently, Krause, James Rossie (an Associate Professor in the Department of Anthropology at Stony Brook University) and 11 other scientists published the results of their extensive analysis in the journal Nature.

The creature, which they have named Adalatherium hui, has numerous distinctive features, including an inexplicable and unique hole on the top of its snout, and an unusually large body for a mammal of its era. The fossil is the most complete for any Mesozoic mammal discovered in the southern hemisphere.

“The fossil record from the northern continents, called Laurasia, is about an order of magnitude better than that from Gondwana,” which is an ancient supercontinent in the south that included Africa, South America, Australia and Antarctica, Krause explained in an email. “We know precious little about the evolution of early mammals in the southern hemisphere.”

This finding provides a missing piece to the puzzle of mammalian evolution in southern continents during the Mesozoic Era, Krause wrote.

The Adalatherium, whose name means “crazy beast” from a combination of words in Malagasy and Greek, helps to broaden the understanding of early mammals called gondwanatherians, which had been known from isolated teeth and lower jaws and from the cranium of a new genus and species, Vintana sertichi, that Krause also described in 2014.

The closest living relatives of gondwanatherians were a group that is well known from the northern hemisphere, called multituberculates, Krause explained.

The body of Adalatherium resembled a badger, although its trunk was likely longer, suggested Krause, who is a Distinguished Service Professor Emeritus at Stony Brook. 

Krause called its teeth “bizarre,” as the molars are constructed differently from any other known mammal, living or extinct. The front teeth were likely used for gnawing, while the back teeth likely sliced up vegetation, which made probably made this unique species a herbivore.

The fossil, which probably died before it became an adult, had powerful hind limbs and a short, stubby tail, which meant it was probably a digger and might have made burrows.

Rossie, who is an expert in studying the inside of the face of fossils with the help of CT scans, explored this unusually large hole in the snout. “We didn’t know what to make of it,” he said. “We can’t find any living mammal that has one.”

Indeed, the interpretation of fossils involves the search for structural and functional analogs that might suggest more about how it functions in a living system. The challenge with this hole, however, is that no living mammal has it.

Gathering together with other cranial fossil experts, Rossie said they agreed that the presence of the hole doesn’t necessarily indicate that there was an opening between the inside of the nose and the outside world. It was likely plugged up by cartilage or other soft tissue or skin.

“If we had to guess conservatively, it would probably be an enlarged hole that allowed the passage of a cluster of nerves and blood vessels,” Rossie said. 

That begs the question: why would the animal need that?

Rossie suggests that there might have been a soft tissue structure on the outside of the nose but, at this point, it’s impossible to say the nature of that structure.

The Associate Professor, who has been a part of the research team exploring this particular fossil since 2012, described the excitement as being akin to opening up a Christmas present.

“You’re excited to see what’s in there,” he said. “Sometimes, you open up the box and see what you were hoping for. Other times, you open the box and say, ‘Oh, I don’t know what to say about this [or] I don’t know what I’m looking at.’”

For Rossie, one of the biggest surprises from exploring this fossil was seeing the position of the maxillary sinus, which is in a space that is similar across all mammals except this one. When he first saw the maxillary sinus, he believed he was looking at a certain part of the nasal cavity, where it usually resides. When he studied it more carefully, he realized it was in a different place.

“All cars have some things in common,” said Rossie, who is interested in old cars and likes to fix them. The common structural elements of cars include front and back seats, a steering wheel, and dashboard. With the maxillary sinus “what we found is that the steering wheel was in the back seat instead of the front.” 

A native of upstate Canton, which is on the border with Canada, Rossie enjoyed camping growing up, which was one of the initial appeals of paleontology. Another was that he saw an overlap between the structures nature had included in anatomy with the ones people put together in cars.

A resident of Centerport, Rossie lives with his wife Helen Cullyer, who is the Executive Director of the Society for Classical Studies, and their seven-year-old son.

As for the Adalatherium, it would have had to avoid a wide range of predators, Krause explained, which would have included two meat-eating theropod dinosaurs, two or three large crocodiles and a 20-foot-long constrictor snake.