Episode 268 is all about Dryptosaurus, New Jersey’s smaller cousin of T. rex.

Big thanks to all our patrons! Your support means so much to us and keeps us going! If you’re a dinosaur enthusiast, join our growing community on Patreon at https://www.patreon.com/iknowdino.

You can listen to our free podcast, with all our episodes, on Apple Podcasts at: https://itunes.apple.com/us/podcast/i-know-dino/id960976813?mt=2

In this episode, we discuss:

News:

• Two new dinosaurs Isasicursor & Nullotitan were described from Southern Argentina source
• Virginia Living Museum is having a dinosaur year, with two exhibits source
• Jurassic Dinosaur Park is being built this year in Chongqing China source
• A glow-in-the-dark dinosaur show is coming to Michigan on January 25 source
• There is a DinoFest in Christchurch, New Zealand from Jan 9-18 source
• There are rumors that next season of Power Rangers will have dinosaurs source
• Moon Girl and Devil Dinosaur: Full Moon has just been released source
• The new VR game Dinosaur Island has been released source
• The game Dino Crisis is getting updated for PC as Dino Crisis Rebirth source
• If the Death Star hit a planet it would have caused a “dinosaur-sized extinction event” source

The dinosaur of the day: Dryptosaurus

• Tyrannosauroid that lived in the Cretaceous in what is now New Jersey, US
• Large, bipedal carnivore
• Estimated to grow up to 25 ft (7.5 m) long
• Weighed about 1.7 tons (based on one specimen)
• Famous because of Charles Knight painting of Leaping Laelaps (used to be Laelaps)
• Charles Knights’ Leaping Laelaps was one of the first (maybe the first) depiction of theropods as active and agile
• One of the Bone Wars dinosaurs (episode 250)
• May have had an arctometatarsalian foot, like Albertosaurus and Tyrannosaurus, where the third toe is pinched in between the second and fourth toes
• Had relatively short arms, and long fingers
• But they were long arms, compared to dinosaurs like T. rex
• Had large hands with three fingers, though Brusatte and others in 2011 found it may have been similar to derived tyrannosaurids and may have had only two functional fingers
• Had 8-inch, talon-like claws
• Having the big hands may mean that tyrannosauroids did not uniformly shrink their forelimbs
• May be possible tyrannosauroids arms got shorter before their hands got smaller (need more fossils to know)
• Had sharp, serrated teeth
• May have used arms and jaws when hunting and eating prey
• Not clear what it ate (not many Cretaceous dinosaurs from the East Coast of the US known)
• May have been hadrosaurids, nodosaurs (but too much armor)
• Lived in a coastal environment
• During the Late Cretaceous there was a warm inland sea that separated western and eastern North America
• Because of the sea, it was isolated from Tyrannosaurus and Triceratops and other dinosaurs of the west, and may have had more generalist features, like earlier dinosaurs
• Not many fossils known
• Described by Edward Drinker Cope 1866
• Laelaps means “hurricane” or “storm wind” and is the name of the dog in Greek mythology that always caught what it hunted (but the name Laelaps had already been used for a mite)
• Renamed by Othniel Charles Marsh 1877
• Type species is Dryptosaurus aquilunguis
• Genus name means “tearing lizard”
• Species name refers to its three-fingered hand, and how it has claws like an eagle’s
• One of the first theropods known (before Dryptosaurus, only theropod teeth had been found)
• Type specimen found in New Jersey, in the West Jersey Marl Company Pit (Hornerstown Formation in Barsboro)
• Quarry workers collected the specimen
• Type specimen includes a fragmentary maxilla, fragmentary right dentary, vertebrae, parts of the hand, parts of the pubic bones, left femur, left tibia, left fibula, left astragalus
• Probably a mature specimen
• A few different names and species (most considered dubious)
• Cope named Laelaps trihedrodon in 1877 based on a partial dentary that’s now missing, found in Colorado (Morrison Formation). Five partial tooth crowns that were thought to be Laelaps trihedrodon are now thought they could belong to Allosaurus
• Cope named Laelaps macropus based on a partial hind limb that Joesph Lediy had throught was Coelosaurus (but had longer toes). In 2017, it was named a new genus, Teihivenator
• Considered to be a primitive tyrannosauroid, though it took some time (classified in the past as megalosaurid, coelurosaur, etc.)
• Gary Vecchiarelli worked on Project: Dryptosaurus, and he reviewed the history and significance of Dryptosaurus, with the goal to put a full reconstruction Dryptosaurus on display at the New Jersey State Museum, which I think is the skeletal Leaping Laelaps they have had on display since 2016
• Paleoartist Tyler Keillor crowdsourced funding and made a life sized replica of Dryptosaurus for the Dunn Museum in Libertyville, Illinois

Fun Fact: Ireland is missing dinosaur fossils because the Mesozoic rock eroded a long time ago, even then, most of the finds are marine.

Sponsors:

Our book 50 Dinosaur Tales is available now! Get the collection of dinosaur stories and facts from recent discoveries by going to bit.ly/iknowdinostore It’s available as an audibook, ebook, and paperback.