Serendipity and Dinosaurs

"At that point [of discovery] I kind of started freaking out because I knew what it was right away and it was one of these exceptionally rare animals."
"It's the only one of the more advanced troodontids that do this [the pubis bone rotated backwards]. Every other one, it's directly pointing straight down."
"We knew right away that it was something different. It represented something we had never seen before."
"That's when everything fell together and we were able to confirm that there were in fact two different species in the Dinosaur Park Formation, instead of just one."
Aaron van der Reest, paleontology student, University of Alberta

Hip bones of Latenivenatrix mcmasterae, unearthed by a University of Alberta paleontology student, are shaking up the family tree of a group of small meat-eaters that lived 75 million years ago. (Julius Csotonyi/University of Alberta)

Two new dinosaur classifications have now emerged, taking the place of Troodon formosus, no longer considered by paleontology study as a unique and valid species. The new classifications are Stenonychosaurus inequalis, and Latenivenatrix mcmasterae. Both mouthfuls of pronunciation, the latter representing a tribute to the late mother of paleontology student Aaron van der Reest. As the discoverer of a rare, intact dinosaur bone, the unearthing of which revealed that an hitherto-unknown species was represented by it, he had the honour of naming the two new classifications.

And how better to honour the mother whose support for her son's ambitions from childhood forward to become a paleontologist hastened his dream? "She looked at me [before her untimely death of cancer] and just told me if it was the last thing that she could do for me, that would be [his financial inheritance at her death] what she would choose." The reason being that he had been unable to complete funding his university studies, due to a lack of income.

As a teen-ager he was given an especial gift from his mother in the form of tickets to attend a University of Alberta lecture by paleontologist Philip Currie. On arrival at the lecture theatre, he discovered that it had been arranged for his seating to be at the head table, alongside his childhood hero. The very same man who many years later was to become his undergraduate supervisor. "Having brought my first find full circle, from discovery to publishing my research three years later, has been really incredible. I can't think of a better way to honour her memory."

Moving forward a few years, Aaron van der Reest was in Dinosaur Provincial Park, southeast of Calgary, as part of his undergraduate studies doing field work in 2014 when he and his partner saw a bone prominently sticking out of the ground close to a collection of other, smaller, bone fragments. The one that had drawn their attention turned out to be the pelvis of what was initially believed to be a Troodon formosus. Such a well-preserved bone was rare to come across.

But van der Reest's attention was riveted disbelievingly on the bone, for the fact that it, a pubis bone was rotated backward. This highly unlikely hip bone discovery spurred him to more closely examine cranial bones that had been collected previously, in southern Alberta. What he discerned from his investigations into both the cranial and the newly-discovered hip bone was a mismatch, leading to the conclusion that Troodon formosus does not represent a species at all.

This research was published in the Canadian Journal of Earth Sciences, which also elucidates on the two new classifications taking the place of the now-defunct species classification.
"Troodon formosus has been found from Mexico all the way to Alaska, spanning a 15 million year period -- a fantastic and unlikely feat."

"The hips we found could ultimately open the door for dozens of new species to be discovered. Researchers with other specimens now have two new species for comparison, widening our ability to understand the Troodontid family tree in North America."
"This new species is the largest of the troodontids ever found anywhere in the world, standing nearly two metres at the head and close to 3.5 metres long. It's about fifty per cent larger than any other troodontids previously known, making it one of the largest deinonychosaurs (raptor like dinosaurs) we currently recognize."

Journal Reference:

1. Aaron J. van der Reest, Philip J. Currie. Troodontids (Theropoda) from the Dinosaur Park Formation, Alberta, with a description of a unique new taxon: implications for deinonychosaur diversity in North America. Canadian Journal of Earth Sciences, 2017; 919 DOI: 10.1139/cjes-2017-0031

Life reconstruction of the newly discovered Latenivenatrix mcmasterae by Julius Csotonyi.

"Troodon formosus has been found from Mexico all the way to Alaska, spanning a 15 million year period—a fantastic and unlikely feat," explained van der Reest, a graduate student of renowned paleontologist Philip Currie.
"The hips we found could ultimately open the door for dozens of new species to be discovered," said van der Reest. "Researchers with other specimens now have two new species for comparison, widening our ability to understand the Troodontid family tree in North America."


Read more at: https://phys.org/news/2017-08-dino-hips-discovery-unravels-species.html#jCp

"Troodon formosus has been found from Mexico all the way to Alaska, spanning a 15 million year period—a fantastic and unlikely feat," explained van der Reest, a graduate student of renowned paleontologist Philip Currie.
"The hips we found could ultimately open the door for dozens of new species to be discovered," said van der Reest. "Researchers with other specimens now have two new species for comparison, widening our ability to understand the Troodontid family tree in North America."


Read more at: https://phys.org/news/2017-08-dino-hips-discovery-unravels-species.html#jCp