Turkana Lake fossils recorded in 3D

The cracked and broken bones of a 1.8-million-year-old crocodile, elephant and giant tortoise are now recorded in meticulous detail, thanks to cutting-edge 3D scanners.

Louise Leakey and Denis Baev scan the fossilized shell of a giant tortoise. It took them 
about two hours to scan the shell because they had to scan both the inside and 
outside to record all of its details, Baev said [Credit: Artec Group]

When the bones were discovered at the Turkana Lake Basin in northern Kenya in the 1970s, they were in considerably better shape than they are now. But at the time, the fossils were too large to safely transport to Nairobi, a 3.5-day boat trip from the site.

Instead, the paleontologists who discovered them — the famous Leakey family — built enclosures for the fossils. "They had to be left there, so that’s why they were turned into these field exhibits so that people could see them there," said paleontologist Louise Leakey.

In September and October of this year, Leakey and her colleagues returned to the fossils to record their shapes with 3D scanners. They will put the scanned images online to share them with researchers and fossil enthusiasts the world over, saving them a trip to the remote Kenyan site.

Denis Baev takes a 3-dimensional scan of the crocodile, whose long snout likely helped
 it catch fish during its lifetime 1.8 million years ago [Credit: Artec Group]

Over time, weather and vandals took their toll on the ancient remains, "so that’s why I was particularly eager to get the record or digital copy," Leakey told Live Science in an email.

On their trip, Leakey and her colleagues scanned two ancient crocodiles, a prehistoric elephant, a giant tortoise and countless other fossils — no small achievement, given that the team worked on days when temperatures reached 95 degrees Fahrenheit (35 degrees Celsius), and alongside large insects and scorpions at night, said Denis Baev, the head of the product requirements department at Artec, the company that donated the 3D scanners for the trip.

"The bugs were the most difficult part to deal with," Baev said. "You can't imagine how many bugs there were."

Turkana treasure trove

For the Leakeys, paleontology is a family business. Louise's grandfather Louis Leakey helped determine that human evolution began in Africa. Her grandmother Mary discovered the preserved footprints at Laetoli in Tanzania, one of the oldest pieces of evidence of primate bipedal walking. Louise's parents, Richard and Meave Leakey, continued the family's fieldwork, especially at Turkana Basin.

A 1.8 million year-old crocodile skull gets 3D scanned by Denis Baev, the head of the
 product requirements department at Artec. Such scanning records the details and
 dimensions of fossils. It's likely that people had vandalized and broken the crocodile
 fossil since the Leakey team uncovered it decades ago, he said 
[Credit: Artec Group]

It was in 1968 that Richard Leakey set up an expedition in northern Kenya, she said. One famous find was that of the 1.6-million-year-old Turkana boy, discovered in 1984 by Kamoya Kimeu, a fossil hunter who worked on Richard Leakey's team. Turkana boy was likely between 9 and 12 years old when he died.

"He obviously fell into a swamp, which is why his bones were so complete and they weren’t scavenged by animals," Leakey said.

Fossils at Lake Turkana are often fragmentary, making Turkana boy's near-complete skeleton a rare find that helped paleontologists learn about the body proportions, brain size and diet of his species. But the Turkana area has yielded countless other fossils, including those scanned on the latest trip. "There are literally fossils on the ground everywhere," Baev said.

Scanning spree

The scanners enabled the team to capture detailed, three-dimensional images of fossils before researchers attempt to move them to a more secure location, likely in Nairobi or the Turkana Basin Institute, a nonprofit research center founded by Richard Leakey and Stony Brook University in New York.

This 3D scan of part of the crocodile fossil shows the ancient animal's mandible 
in detail. The researchers used two 3D scanners made by a company called Artec,
 which donated the devices for the trip [Credit: Artec Group]

"Once you have a digital model, you can do comparisons of morphology, you can do comparisons of teeth, there’s any number of studies that can come out of it," Leakey said.

The 1.8-million-year-old elephant skeleton, discovered in 1974 by a team led by Richard Leakey, had a fairly complete skeleton, including the skull, two tusks, the mandible, limb bones, ribs, vertebrae and foot bones.

The elephant (Elephas recki) is an ancestor of the modern-day Asian elephant. The researchers used two three-dimensional scanners, "Eva," which provides a quick scan, and "spider," which can capture more detail.

"The mandible of the elephant was very well-preserved," Baev said. "We used spider to get as many details about the teeth as possible."

A 3D digital representation of the crocodile fossil. Now, instead of traveling
 to remote Kenya to see the fossils, researchers can access and study 
the 3D scans online [Credit: Artec Group]

They also scanned a 1.8-million-year-old giant tortoise, found by Richard and Meave Leakey's team in the early 1980s, and excavated by Meave and her children, Samira and Louise, in 1984. The finding is one of the most complete fossils of a giant tortoise in Africa, Baev said.

"Actually, a human can take a bath in there," Baev said. "It's very big."

Vandals had damaged one of the two crocodile skeletons, possibly by throwing the head, Baev said. Some of its ribs, teeth and other bones are now missing or broken, he added. The scanner allowed the pieces to be digitally reconnected.

"I have used the software to connect these two pieces and to make them whole again," he said.

Another crocodile (Euthecodon brumpti) has a slender snout suited for eating fish, and also dates to 1.8 million years ago. Louise Leakey sacrificed her toothbrush to help clean the fossil before the scanning because the group had left their tools at camp, Baev wrote in his blog.

Discovered in 1974, this prehistoric elephant (Elephas recki) is larger than its
 modern ancestor, the Asian elephant. The fossil includes the elephant's skull, tusks,
 mandible, limb bones, ribs, vertebrae and foot bones [Credit: Artec Group]

"For me it was amazing how great the condition of the fossil was," Baev told Live Science. "[But Louise] was actually quite mortified by its condition. She told me it used to be much better."

Louise Leakey said that the nearly complete crocodile skeleton was a find akin to Lucy, a key 3.2-million-year-old fossilized hominid found in Ethiopia in 1973.

"This is crocodile Lucy," she said. "And she was left in the field because she’s too big to move. She’s been very damaged over time — that’s why it was particularly important to get a scan."

For comparisons, at the Turkana Basin Institute the team also scanned the remains of modern animals, including a crocodile, giraffe, rhino, tortoise, buffalo and blue wildebeest. They also scanned hominid skull casts kept at the institute, including Turkana Boy, and 1.5-million-year-old Homo erectus footprints in Illeret, a village close to the institute.

On their last day at the institute, an archaeologist who had just arrived from Nairobi happened upon the group.

"As he saw the 3D models, he was amazed," Baev said. "He said, 'But that means I don't have to travel this far to see the fossils.' I imagine that people from all around the world can take a look at all of the fossils we have uncovered."

Author: Laura Geggel | Source: LiveScience [December 24, 2014]