New Mexico Skull Of T-Rex Relative: High-res Images May Reveal Evolutionary Clues

LOS ALAMOS, NM — Researchers at the Los Alamos National Laboratory and the New Mexico Museum of Natural History and Science created the highest resolution scan ever done of the inner workings of a fossilized tyrannosaur skull, officials said, uncovering new clues that might shed some light on how the dinosaur evolved.

Officials presented some of their findings after peering deeper into the skull of a tyrannosauroid dinosaur dubbed "Bisti Beast," a T. rex relative that lived 74 million years ago in current-day northwestern New Mexico. The images detail the dinosaur's brain and sinus cavity, the pathways of some nerves and blood vessels and teeth that formed but never emerged.

Collaboration creates highest-resolution scan of a large #dinosaur skull | #Paleontology #Tomography | https://t.co/pOZwGg47Sk pic.twitter.com/oWFYSu0lOs
— Los Alamos Lab (@LosAlamosNatLab) August 15, 2017

"The CT scans help us figure out how the different species within the T. rex family related to each other and how they evolved," said Thomas Williamson, the museum's curator of paleontology. (For more information on this and other New Mexico stories, subscribe to Patch to receive daily newsletters and breaking news alerts. If you have an iPhone, click here to get the free Patch iPhone app.)

T. rex and other tyrannosaurs were huge, dominant predators, but they evolved from much smaller ancestors.

The fossilized remnants of the Bisti Beast, or Bistahieversor sealeyi, were found in 1996 in the Bisti/De-Na-Zin badlands near Farmington, New Mexico.

The species lived about 10 million years before T. rex, and scientists have said it represents the foundation of the tyrannosaurs with its big-headed, bone-crushing characteristics and small forelimbs.

Williamson said the Bisti Beast was a surviving member of a lineage that retained many primitive features from even farther back than when tyrannosaurs underwent their transition to crushing bones.

Officials said the dinosaur's skull is the largest object to date for which full, high-resolution neutron and X-ray CT scans have been done at Los Alamos. The technology is typically used for the lab's work on defense and national security.

The thickness of the skull required stronger X-rays that those typically available to penetrate the fossil, the lab said. That's where the lab's electron and proton accelerators came in.

"It turns out that high-energy neutrons are an interesting and unique way to image something of this size," said Ron Nelson, who works with the lab's physics division. The skull spans 40 inches.

The team, which included staff from the University of New Mexico and the University of Edinburgh, is scheduled to present its work at a paleontology conference in Canada next week.

By SUSAN MONTOYA BRYAN, Associated Press

Photo credit: Nick Njegomir/Los Alamos National Laboratory