In our 44th episode of I Know Dino, we had the pleasure of speaking with Christopher Lowman, a fourth year graduate student at UC Berkeley, studying archaeology, who took part in a Royal Tyrell Museum public program and saw a Pachyrhinosaurus being excavated.
We also talk about Pachyrhinosaurus, a “horned” dinosaur that actually had bosses, not horns.
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In this episode, we discuss:
- The dinosaur of the day: Pachyrhinosaurus, whose name means “thick nosed lizard”
- Lived in Cretaceous in North America
- Discovered by Charles M. Sternberg in Alberta Canada in 1946, named the species in 1950
- Charles M. Sternberg also named Edmontonia, he was a Reverend’s son and his sons George, Charles, and Levi also hunted for fossils
- First Pachyrhinosaurus fossils may have been discovered in 1880, but the ones found in 1946 were the ones leading to it being named in 1950
- Partial skulls and other fossils have been found in Alberta and Alaska (different species), but not many fossils available to be studied until the 1980s
- Technically Pachyrhinosaurus is a “horned” dinosaur, but it didn’t have that many horns
- Skulls had flattened bosses (instead of horns), with a large one over the nose and a smaller one over the eyes
- Bosses are big, flattened bulges
- Adult Pachyrhinosaurus had thick sheaths and padding to cover their nasal bosses
- Also had a pair of horns from the frill that grew upwards, and small ornamental horns on the skull (varied between species and individuals)
- In the 70s, some paleontologists thought that the bosses on Pachyrhinosaurus‘ face were just the base for giant horns that may have broken off after they died, but no giant horns have been found so far
- In 2013, PLOS One study called “An Immature Pachyrhinosaurus perotorum (Dinosauria: Ceratopsidae) Nasal Reveals Unexpected Complexity of Craniofacial Ontogeny and Integument in Pachyrhinosaurus” found a new juvenile specimen of P. perotorum in Alaska that showed the changing stages of the nasal boss “reveals a more complicated craniofacial ontogeny in Pachyrhinosaurus than previously thought”
- At one point the two nasal bones were fully fused together and the nasal posterior may have quickly elongated to accomodate the nasal boss formation
- Pachyrhinosaurus had bones on its heads, possibly used for head butting (find mates or fight)
- Specimens have been found with broken ribs and partially healed ribs, so they may have flanked each other
- May have charged predators like a modern rhinosaurus
- Three species found: P. lakustai from Wapiti Formation (73.5-72.5 million years ago), P. canadensis from lower Horsehose Canyon Formations (71.5-71 million years ago), P. perotorum from the Prince Creek Formation in Alaska (70-69 million years ago)
- P. canadensis was named in 1950, P. lakustai in 2008, P. perotorum in 2012
- Type species is P. canadensis
- 2008: Philip Currie, Wann Langston Jr. and Darren Tanke made a detailed monograph of the skull of a Pachyrhinosaurus and classified it as a second species, P. lakustai, named after the person who discovered it
- A Pachyrhinosaurus bonebed was found in Alberta in the late 1980s, where paleontologists found 3500 bones and 14 skulls (possibly the group tried and failed to cross a river during a flood); fossils were from juveniles and adults, so they may have taken care of their young
- Al Lakusta found the bonebed in 1973
- Pachyrhinosaurus bones found in the bonebed in the 1980s had convex (curved outward) and concave (curved inward) bosses, possibly due to erosion. P. lakustai named after Al Lakusta (science teacher from Alberta)
- P. perotorum is named after Ross Perot
- Species named after Perot because he funded scientific expeditions
- P. canadensis had eye and snout bosses nearly together, with curved backwards pointing horns on the frill, two flattened horns that point forwards and down from the top of the frill, and a flat round nasal boss
- P. lakustai sometimes has been found with two curved backwards pointing horns on the frill, and had a jagged comb extension on the tip of the nasal boss, a pommel on the front of the nasal boss, and a comb like horn rising from the middle of the frill behind the eyes
- P. perotorum had eye and snout bosses almost together, a jagged comb extension on the tip of the nasal boss, and a narrow dome in the center of the upper portion of the nasal boss
- The boss on the nose was different for each species. P. lakustai and P. perotorum had a jagged, comb-like extension at the tip, P. perotorum had a narrow dome in the middle of the boss, P. lakustai had a structure coming out of the front, P. canadensis had a flat, rounded boss, P. perotorum had two flattened horns from the top of the frill and P. lakustai had a comb-like horn
- P. canadensis and P. perotorum, bosses grew together, separated by a narrow groove (bosses over the nose and eyes)
- P. lakustai, two bosses had a large gap
- P. canadensis and P. lakustai had two small, curved horns that pointed backwards and came from the frill (P. perotorum did not have this, and not all P. lakustai had them, so may have changed based on age or gender)
- P. canadensis had a flat, round nasal boss, P. perotorum had a domed top, some P. lakustai‘s frills had “unicorn horns” but may be the way the fossils were preserved (from the ones in the bonebed)
- In 2014, Darla Zelenitsky from University of Calgary announced the find of a well-preserved Pachyrhinosaurus skull (75-80% complete), found in Alberta’s Badlands
- Skull is an adult’s and is large (possibly the biggest Pachyrhinosaurus skull discovered)
- Found the skull in October 2013, but it took a few months to remove the 5 tons of rock to get the skull out
- May be a new species or may be part of the 3 existing ones
- Skull is 6.5 to 8 ft (2-2.5 m) long, and animal was 6 m long, so was very top heavy
- Largest Pachyrhinosaurus species was 26 ft (8 m) long and weighed about 4 tons
- Lived near other dinosaurs including ceratopsians Anchiceratops and Montanoceratops, hadrosaur Edmontosaurus regalis, theropods including Saurornithoides, Saurornitholestes and Troodon, possibly the ornithopod Thescelosaurus and tyrannosaurid Albertosaurus
- Mostly hadrosaurs in the area
- Pachyrhinosaurus had a short tail
- 18-23 ft (5.5-7m) long
- May have been fast, running up to 20 mph
- Had small, primitive hearing apparatus, so probably not very good hearing
- Also reduced olfactory centres, so probably had a poor sense of smell
- Had poor vision too, based on a study of its brain cavity finding a not well developed optic center
- Herbivores, with strong cheek teeth (ate fibrous plants)
- Replaced teeth regularly
- Beak at front of snout, probably cropped vegetation; had rows of teeth
- Probably ate cycads, palms
- May have eaten newly evolved flowering plants
- May have migrated to warmer climates
- May have migrated, following coastal plains, or stayed in the same area. Not sure why they’re found in Alberta and Alaska
- Fossils often found near Edmontosaurus (may have traveled together?)
- May have reached maturity at around 9 years old, based on Gregory Erickson’s and Patrick Druckenmiller’s study of Pachyrhinosaurus femurs (probably only lived to about 19 or 20 years old)
- Pachyrhinosaurus was the official mascot of 2010 Arctic Winter Games because a bonebed was near Grand Prairie Alberta (competition for athletes in the north)
- Pachyrhinosaurus was the star of Walking with Dinosaurs: The Movie in 2013 (featured Patchi and his brother Scowler and their herd
- Pachyrhinosaurus was also in Disney’s Dinosaur in 2000 (awful lot like Land Before Time)
- Pachyrhinosaurus also in the History Channel TV show Jurassic Fight Club
- The Phillip J. Currie Museum opened up in the beginning of September, and in addition to watching documentaries and looking at lifelike skeletons, visitors can build a pachyrhinosaurus with magnets on the wall
- Pachyrhinosaurus is part of the clade Pachyrostra, which is part of the tribe Pachyrhinosaurini, which is part of the family Ceratopsidae, which is part of the clade Marginocephalia
- Marginocephalia means “fringed heads” and includes pachycephalosaurids and horned ceratopsians (all herbivores, with bony ridge or frill at back of the skull)
- Lived in Jurassic and Cretaceous
- Ceratopsidae were quadrupedal herbivores from the Cretaceous, with most living in North America (some in Asia)
- Had beaks, rows of shearing teeth, and horns and grills
- Subfamilies are Chasmosaurinae of Centrosaurinae
- Pachyrhinosaurini was a subfamily of Centrosaurinae
- Fun Fact: The Prince Creek Formation (PCF) of northern Alaska preserves one of the most diverse and prolific assemblages of polar dinosaurs known anywhere in the world. To date, evidence for at least 13 different dinosaurian taxa are known from early Maastrichtian horizons of the unit, including five ornithischians, seven non-avian theropods, and an avialan theropod
For those who may prefer reading, see below for the full transcript of our interview with Christopher:Continue Reading …