Pachyrhinosaurus perotorum. Illustration by Karen Carr
Illustration by Karen Carr
Dinosaurs on the North Slope

twitter@BLMAlaska held a Twitter Chat with Dr. Fiorillo and BLM's Paleontologist Harley Armstrong, on Thursday Dec 8, 2011, from 11 a.m.–1 p.m. AKST (2 p.m.–4 p.m. CST/3 p.m.–4 p.m. EST). @BLMAlaska Tag with #alaskadinosaur 

Weighing in at about four tons, standing seven feet high on four legs and about 18 feet long, it’s roughly the size of an rhino, eats plants and lived approximately 70 million years ago. Paleontologist Anthony R. Fiorillo, Ph.D., and his team discovered the new species of dinosaur, the Pachyrhinosaurus perotorum, near the Colville River on BLM-managed lands in Alaska. To help dinosaur enthusiasts understand more about the dinosaur, BLM-Alaska and the Museum of Nature & Science are hosting a live chat on Twitter with two of the nation’s leading paleontologists.

@BLMAlaska held a Twitter Chat with Dr. Fiorillo and BLM's Paleontologist Harley Armstrong, on Thursday Dec 8, 2011, from 11 a.m.–1 p.m. AKST (2 p.m.–4 p.m. CST/3 p.m.–4 p.m. EST).During the #alaskadinosaur tweet chat, Dr. Fiorillo and Armstrong will answer questions about the Pachyrhinosaurus perotorum and other dinosaurs on Alaska’s North Slope. Members of the public are invited to follow the tweet chat on with the hashtag #alaskadinosaur. If you don’t have a Twitter account or can’t join us between 11 a.m. and 1 p.m., you can submit your question to us in advance on Twitter or by email at

Kikak excavation 2006. Photo Credit: Museum of Nature & Science in Dallas,TexasDr. Fiorillo and his team discovered this new species near the Colville River on BLM-managed lands in Alaska. Fiorillo announced the discovery at the Society of Vertebrate Paleontology 71st Annual Meeting. The new species was named the Pachyrhinosaurus perotorum in recognition of the Perot family (Margot and Ross Perot and their children), who have demonstrated a long history of supporting science education for the public.   A reconstruction of the Pachyrhinosaurus perotorum will be installed in the Life: Then and Now Hall, which will be part of the new Perot Museum of Nature & Science, when it opens in Dallas’ Victory Park in early 2013. Read more about the four-ton, plant eating giant.

 Tweet Cadre

Paleontologist Anthony R. Fiorillo, Ph.D

Dr. Anthony R. FiorilloAs far back as he can remember Dr. Anthony R. Fiorillo has only wanted to do one of two things professionally, play centerfield for the New York Yankees or study dinosaurs. Much to the detriment of his parents’ retirement plans, he studies dinosaurs.

Dr. Fiorillo received his Bachelor of Science degree from the University of Connecticut and his Master of Science degree from the University of Nebraska. He completed his Ph.D. work in vertebrate paleontology at the University of Pennsylvania in 1989. For the next two years he was the Rea Postdoctoral Fellow at the Carnegie Museum of Natural History, and then a museum scientist at the Museum of Paleontology. Since 1995 he has been the Curator of Earth Sciences at the Museum of Nature and Science in Dallas, Texas, and has been working in Alaska on various dinosaur projects since 1998. His work in over a dozen units of the National Park Service won him national recognition in 2000 and again in 2007 with the National Park Service, Alaska Region Natural Resource Research Award. He was also named a Fellow of the Geological Society of America in 2008. For him, the appeal of the work in Alaska is the result of the combination of intellectual pursuit and the rigors of working in the Arctic environment. (Bio from Palaeo-electronica)

BLM Paleontologist Harley J. Armstrong

Harley ArmstrongHarley Armstrong serves in the Colorado State Office (CSO) as a BLM Regional Paleontologist for Colorado, Alaska, and Eastern States. Armstrong is also the CSO Science Coordinator, plus works to update the CSO website with information on Areas of Critical Environmental Concern and with gold collecting information. Prior to 2006, Armstrong’s BLM duty station was in Grand Junction from 1993 to 2006. Armstrong has prior work experience as the Curator of Paleontology from 1985 to 1993 at the Museum of Western Colorado in Grand Junction. He has worked as an archaeologist and a paleontologist from 1978 to 1985 doing consulting survey and mitigation work in Colorado, Utah, and Wyoming. Prior career-oriented work has included internships in geology and paleontology at both the Museum of Western Colorado in Grand Junction, and at the University of Colorado Museum in Boulder. Field courses with components in archaeology, geology, and paleontology, have included summers in 1977 in central Alaska, and 1979 in central Wyoming. Armstrong has authored several monographs, publications and presentations about paleontological and cultural resources. Armstrong has also helped design 7 outdoor trails interpreting paleontological and geological resources.

Dr. Ron Tykoski, Chief Fossil Preparator

Ron TykoskiDr. Tykoski joined the Museum in June of 2005, after earning a Ph. D. in Geological Sciences from the University of Texas at Austin. He also holds a Master’s of Science degree from UT-Austin and a B.S. from the University of Michigan-Ann Arbor, both in Geological Sciences.

Dr. Tykoski became a paleontologist because of his childhood fascination with prehistoric beasts, paleontology and Earth history – passions he never outgrew. He began his career as a young docent at the Exhibit Museum of Natural History on the campus of the University of Michigan-Ann Arbor, and continued to work there throughout his undergraduate studies.

Dr. Tykoski continues his commitment to academia by contributing articles to scientific journals, books such as The Dinosauria, and dinosaur encyclopedias. He has been an active member of the Society of Vertebrate Paleontology since 1994. He relishes the thrill of discovery and the knowledge that at any moment, he may be the first person in the human history to see something new emerge from a piece of rock.

Dr. Tykoski credits his wife, MJ, and their two children, Stephen and Christine for supporting his highly-accomplished career.

Resources for Tweet Chat

twitterQuestions and Answers from Tweet Chat

Thank you to all that participated in our Tweet Chat. If you didn't make it here's what you missed!

twitter Q: Where can we go for more information on perotorum and the other dinosaurs found in Alaska?
@dallasmns A: You can find more information on the alaskadinosaur at and also

Email icon@BLMAlaska Email Q & A: What dinosaurs were in AK? A motley crew of herbivores, omnivores & carnivores indicate old Arctic was a rich ecosystem

twitter Q: Curious how their mobility compared to more only flat-land dinos? Lived in valleys?
@dallasmns A: this was a flat coastal plain at the time. They moved much like other coastal plain dinos anywhere.

Email icon@BLMAlaska Email Q & A: any other species found near #perotorum? Yes! We found 4 different theropods & a duck-billed dinosaur

twitter Q: Do you have any indication of how they died?
@dallasmns A: the story is complicated... but in general the #perotorum herd died from a stream flood event.

Email icon@BLMAlaska Email Q & A: did #perotorum live by itself or in a herd? They were social & lived in herds. Dr. Fiorillo found 10 buried together.

twitter Q: Dr. Fiorillo, you don't believe the #perotorum were migratory, is that correct?
@dallasmns A: Correct. I do not believe it was migratory.

twitter Q: where was the dinosaur discovered?
@dallasmns A: The #alaskadinosaur was discovered along the Colville River on BLM-managed lands in northern Alaska.

twitter Q: Did you stumble on the dino or were you looking for it in that part of the Colville?
@dallasmns A: We were looking for the #alaskadinosaur in that part of the Colville.

Email icon@BLMAlaska Email Q& A: How did you get #perotorum fossils to Texas? Very carefully! By Boat, helicopter, plane & truck. In that order.

Email icon@BLMAlaska Email Q & A: Why were they so big? Size helped them travel long dist., insulate for climate & defend against (wicked) predators.

twitter Q: Are there plans to promote the latest dinosaur finds in Alaska?
@dallasmns A: the only place the #alaskadinosaur will be recreated will be the Perot Museum of Nature & Science in Dallas in 2013.

twitter Q: I know the @dallasMNS is planning a replica. Are there similar plans in Alaska?
@dallasmns A: there will be several Alaskan dino exhibits in the future Perot Museum of Nature & Science to open in 2013.

twitter Q: did the new Dino have any predators? If so, who were they?
@BLMAlaska A: T. Rex’s cousin snacked on perotorum - we found teeth marks on #perotorum bones from these & other meat eaters

twitter Q: I've never heard the term polar dinosaur before. Interesting. Would it have been a meat eater?
@dallasmns A: The #alaskadinosaur was a plant eater. But there were meat eating dinosaurs living there as well. #alaskadinosaur lived above the ancient Arctic Circle, so it was a polar dinosaur.

Email icon@dallasmns Email Q & A: How well was the #perotorum intact? A: We recovered parts of several skeletons (including a couple of skulls).

Email icon@dallasmns Email Q & A: Did u recover the full skeleton for the #perotorum? No

twitter Q: How did the perotorum use those sideways horns?
@BLMAlaska A: They were for show! #perotorum used them to identify each other and potential mates. 

Email icon@BLMAlaska Email Q & A: what did #perotorum look like? Looked similar to triceratops (with very different horns).

twitter Q: Do you know how it was adapted for the cold?
@BLMAlaska A: #alaska was warmer w/cool dark winters. Maybe adapted by season - grew & ate less in winter.

twitter Q: What sort of climate did alaskadinosaur live in?
@BLMAlaska A: #perotorum lived in polar climate similar to Pacific NW. Long, dark winters!

twitter Q: When did this dinosaur roam the earth?
@dallasmns A: It lived in the latest Cretaceous Period (69- 70million yrs ago). 

twitter Q: Audience Poll: Who would win a dinosaur show-down, perotorum or T. Rex?
@BLMAlaska A: Dr. Tykoski votes for T. Rex “Big teeth. Big jaws. Twice as Big. Do the math!”
@BLMAlaska A: Dr. Fiorillo votes for #perotorum “T.Rex would run screaming” in #alaskadinosaur showdown
@BLMAlaska A: Tie-breaker: Armstrong votes for perotorum “Because today is perotorum’s big day. No one loses on their big day”