The Big Dinosaur Podcast

In our 34th episode of I Know Dino, we had the pleasure of speaking with paleontologist Dr. Jim Kirkland. Dr. Jim Kirkland is the Utah State Paleontologist with the Utah Geological Survey. He has discovered and described a long list of dinosaurs, including the first Jurassic ankylosaur, the oldest horned-dinosaur Zuniceratops, and ornithopods such as Eolambia and Velafrons, and of course Utahraptor. And he has authored and co-authored more than 75 professional papers. He is also adjunct Associate Professor at University of Utah, Salt Lake City, Utah and associate curator of the Natural History of Utah. And he has written a Star Trek novel, called First Frontier, with Diane Carey.

Find out more about Dr. Kirkland on his website at http://ugs.academia.edu/JamesKirkland and follow him on Twitter at @paleojim.

You can listen to our free podcast, with all our episodes, on iTunes at:

https://itunes.apple.com/us/podcast/i-know-dino/id960976813?mt=2

In this episode, we discuss:

• The dinosaur of the day: Utahraptor, whose name means “Utah robber”
• From Cretaceous period
• Species is Utahraptor ostrommaysorum (found in eastern Utah)
• Largest Dromaeosauridae (family, also known as raptors); other dromaeosaurids include Velociraptor and Deinonychus
• Before Utahraptor, paleontologist thought raptors were all small and only lived in the late Cretaceous
• Most dromaeosaurs (raptors) lived towards the end of the Cretaceous, but Utahraptor lived during the early Cretaceous, around 50 million years earlier. So it’s interesting that other raptors were much smaller, since the trend for many dinosaurs was to grow bigger.
• Holotype consists of skull fragments, tibia, claws, and some caudal (tail) vertebrae; is about twice the length of Deinonychus
• Largest Utahraptor is estimated to be 23 ft (7 m) long and weigh around 1,100 lb (500 kg); about same size as a polar bear
• Type species named by Kirkland, Gaston and Burge in 1993 for John Ostrom, paleontologist from Yale University’s Peabody Museum of Natural History and Chris Mays (dino robotics pioneer) from Dinamation International
• Ostrom theorized in the 1970s (before it became widespread) that raptors such as Deinonychus were ancestors of modern birds
• The species was originally going to be named after Steven Spielberg, but as Jim Kirkland mentioned, it was changed at the last minute to avoid a potential lawsuit
• Utahraptor was formally described in 1993 (shortly after Jurassic Park was released)
• In Jurassic Park, the velociraptor is half the size in real life. But the large size is more similar to Utahraptor, some people have said it could be a combination of Deinoychus and Utahraptor
• First fossils of giant dromaeosaurs found in the Brigham Young University’s Dalton Well Quarry (discovered in the late 1960s by Lin Ottinger), and a few specimens were prepared (out of hundreds collected) by Jim Jensen and his crew in 1975
• Bones from Dalton Well were well preserved but a mix of many different individual dinosaurs
• Second group of giant dromaeosaur fossils (including a foot claw) found in 1991 and 1992, during excavations of the Gaston Quarry
• Another, large “carnosaur” was found at the Dalton Well site in addition to Utahraptor, but it’s unclear how the two large theropods lived alongside each other
• A new dromaeosaur was discovered recently (named in 2012) in the Cedar Mountain Formation (where Utahraptor was found). Called Yurgovuchia doellingi, it had a unique tail skeleton similar to Utahraptor (large, flexible tail) and is probably in the same clade as Utahraptor, Achillobator, and Dromaeosaurus (about same size as a coyote)
• Utahraptor was probably warm-blooded (active predator)
• Several claws were found, has a sickle-claw and the rest are called manual claws (tended to be very thin)
• Due to the specialized manual claws, scientists do not think it gave rise to other known dromaeosaurs, and instead there may have been an older common dromaeosaur ancestor (early Cretaceous or late Jurassic)
• Had 9-inch long sickle-claws (nails were probably 15 inches)
• Three fingers on each hand and four-toed feet
• Utahraptor had enlarged toe joints, so that it’s sickle claw could raise up and backward so as not to be injured while running (but flexed claw out when attacking)
• Utahraptor had blade-like manual claws (different from Deinonychus and other smaller dromaeosaurs which had long arms so as to hold its prey while attacking with its sickle-claw it’s possible the force of its kick to the prey “may have dislodged them”) but Utahraptor was much heavier and probably wouldn’t have been thrown off balance due to the force of its kick, so its hands were free to help kill the prey
• Probably had very strong legs, used to slash prey with its sickle-claw
• Based on Utahraptor’s size, it may have been able to make 5-6 feet long cuts with one slash by rotating its limbs and flexing its claw (probably could have killed prey with one kick)
• Bipedal and agile
• Based on the length of the tibia (scientists think it was subequal in length to the femur, like in other large theropods), scientists think Utahraptor were not as fast proportionally as Deinonychus or Velociraptor (would have been at least as fast as iguanodonts in the area and maybe faster than sauropods)
• Like other dromaeisauridae, had a caudal vertebrae to stiffen its tail, for balance
• Utahraptor had blade-like, serrated teeth (one tooth was 45 mm or 1.7 in long)
• Premaxillary teeth are different from other described dromaeosaurs (had simple, blunt serrations, except for Dromaeosaurus–so Utahraptor may be in subfamily Dromaeosaurinae instead of Velociraptorinae)
• Utahraptor had large eyes
• Had a curved, flexible neck
• No feathers found with Utahraptor specimens, but strong evidence that dromaeosaurids had feathers (partly because Microraptor, one of the oldest known dromaeosaurs, had feathers, as well as other dromaeosaurids)
• Utahraptor’s feathers probably gave it an added lift, but would not have flown
• Utahraptor was the most intelligent animal of its time and habitat
• Utahraptor co-existed nodosaur (spiny and armored), iguandons and sauropods
• May have gone after larger prey (iguanodonts, sauropods up to 65 ft or 20 m long)
• Dromaeosaurs are sophisticated hunters, and could hunt prey bigger than themselves (dromaeosaurs that were 11.5 ft or 3.5m long and 70 kg or 150 lb could successfully hunt prey that was 8 m or 26 ft long and 1000-2000 kg or 2200-4400 lbs)
• Utahraptor may have hunted in groups
• Until 2014, only isolated specimens of Utahraptor have been found, but there’s evidence that Deinonychus hunted in packs, so scientists think other dromaeosaurs such as Utahraptor may have hunted in packs too
• 2014: A 16-foot adult, 4 adolescents, and 3-foot baby Utahraptor were found together in Utah, which may give insight into how they behaved (Dr. Kirkland heading the study)
• Kirkland heard about the site in 2001 when a geology student found what looked like a human arm bone, but turned out to be part of a dinosaur foot (hollow bone, which meant carnivore)
• The 9-ton block of sandstone has many Utahraptors in it; fossils re packed tight, some stacked 3 feet thick, so they may have died together or at different times in quicksand
• Dromaeosaurs are some of the rarest dinosaurs in the North American fossil record, according to paleontologist Stephen Brusatte, from the University of Edinburgh
• Kirkland called the find “the Rosetta stone for Utah dinosaur collecting”
• The bones are in sandstone and red mudstone. In the Cretaceous, lakes surrounded the area, and as the lakes drained, it would have turned the ground to quicksand. Probably killed the Utahraptors and preserved them.
• Also in the area was an iguanodont (scent may have attracted the Utahraptors)
• Because of Jurassic Park, raptors are often depicted as pack hunters, but there’s not much actual evidence for it (best evidence is a trackway in China that appears to show a group of dromaeosaurids going after an iguanodontian
• The find may determine whether Utahraptor hunted in packs or not
• Ways to see if they hunted together are if the skeletons show interweaving or the degree the bones were damaged by sun and exposure before being buried, to show if they were buried at the same time or at different times
• Will take years to study fully
• Pictures at http://www.stgeorgeutah.com/news/archive/2015/01/11/ams-scientists-unearth-9-ton-quicksand-block-containing-utahraptor-skeletons/#.VZ2hDxNVhHw
• Robert Bakker (actually suggested the name for the Utahraptor genus) wrote Raptor Red (first novel, published in 1995)
• Told from POV of Utahraptor Raptor Red, using many of Bakker’s theories about dinosaur behaviors, intelligence, and habitats (as well as studies of modern animals)
• Follows a year of Red’s life (loses her mate, finds her sister, struggles to survive)
• Bakker was inspired from Ernest Thompson Seton’s works, which show life through the POV of predators
• Bakker’s goal was to portray predators as more than just evil (empathetic)
• Got mostly positive feedback, but some critics thought the public would think Bakker’s theories on Utahraptors were fact
• One reviewer compared it to Pride and Prejudice (Red’s sister does not approve of Red’s new mate)
• Daily Variety reported in 1996 that producer Robert Halmi Sr. made deals with Jim Henson’s Creature Shop to adapt Raptor Red (and Animal Farm), but no official projects were announced
• In 1999 BBC’s Walking With Dinosaurs portrayed Utahraptor as living in Europe (but it only has been found in the U.S.)
• Can see Utahraptor at the Natural History Museum of Utah, Brigham Young University Museum of Paleontology and USU Eastern Prehistoric Museum
• Many dinosaurs in North America had similar-looking relatives in Europe and Asia during the Cretaceous (because of the continental drift). Utahraptor’s counterpart was Achillobator, a smaller version that lived in central Asia and had extra-thick Achilles tendons in its heels
• Dromaeosaurs are “swift lizards”
• Dromaeosaurs had unique wrist-joints that allowed hands to pivot sideways (similar to a bird folding its wing)
• Dromaeosaurs are evidence that dinosaurs were active, related to birds, and probably warm-blooded
• Dromaeosaurine is a subfamily of Dromaeosauridae
• Another subfamily is velociraptorine
• Dromaeosaurines have stout, box-shaped skulls compared to other subfamilies of dromaeosaurids (narrow snouts); dromaeosaurines had thicker legs (built for strength, not speed)
• Dromaeosaurines lived in the US and Canada, Mongolia, and possibly Denmark and Ethiopia (teeth found in Ethiopia, may have been a dromaeosaurine from the late Jurassic)
• Late Cretaceous dromaeosaurines were small (6 ft or 1.8 m long)
• Fun Fact: Sinosauropteryx, which means “Chinese reptilian wing” is a compsognathid that was described in 1996, and was the first dinosaur not in the Avialae group to have evidence of feathers

For those who may prefer reading, see below for the full transcript of our interview with Dr. Jim Kirkland:Continue Reading …