#callovosaurus

Welcome to DinApril 2026, where instead of recycling my list from last year, I made my father come up with the dinosaurs! Our thirtieth and final day is my father's take on the free day: The Oxford Clay Formation! A male Eustreptospondylus oxoniensis, Callovosaurus leedsi, and Metriacanthosaurus parkeri have been washed out to sea by a storm and struggle to stay afloat, unaware of the hungry Liopleurodon ferox lurking below the debris.

My father's favorite prehistoric animal is Liopleurodon because he saw a clip of the oversized Liopleurodon from Walking With Dinosaurs hunting a Eustreptospondylus, and he wanted the pliosaur to be featured for today's prompt. I, of course, decided not to depict the pliosaur as 82 feet long and instead depicted it as a more realistic (although still rather large) 30 feet long. Fitting that a 30-foot Liopleurodon is featured on the thirtieth day.

This is it, folks. I actually did it! Tomorrow I'm going to make a compilation of all 30 pieces I did this year.

I Know Dino Podcast Episode 287: An interview with Steve Poropat & @AdelePentland from @Swinburne about a new polar ceratosaur from Australia. Plus a fetal Lufengosaurus with #Diplodocus like teeth and an update on the Dueling #Dinosaurs.

Episode 287 is all about Callovosaurus, a Dryosaurid which is featured in some editions of Jurassic Park (the first book).

We also interview Dr. Steve Poropat from Swinburn University & Research associate at Australian Age of Dinosaurs and Adele Pentland PhD candidate at Swinburn University & Research associate at Australian Age of Dinosaurs.

Here’s an artistic rendering of the new…

By Jack Wood on @thewoodparable

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Name: Callovosaurus leedsi

Name Meaning: Callovian Reptile

First Described: 1980

Described By: Galton

Classification: Dinosauria, Ornithischia, Genasauria, Neornithischia, Cerapoda, Ornithopoda, Iguanodontia, Dryomorpha, Dryosauroidea, Dryosauridae

Callovosaurus is our first Dryosaurid, the group of later derived, bipedal Ornithischians that are closely related to the large Iguanodonts we all know and love, like Hadrosaurids. Callovosaurus, in fact, is the earliest known Iguanodontian - dating back to the Callovian age of the Middle Jurassic, approximately 163 million years ago. It is known from a thigh bone fromt eh Oxford Clay formation of Fletton, Cambridgeshire, England. Despite this fragmentary remain, it has been recovered as a Dryosaurid in many analyses, including the Boyd study. It lived in an island ecosystem alongside many ichthyosaurs, plesiosaurs, crocodyliformes, pterosaurs, and other dinosaurs such as Cetiosauriscus, Eustreptospondylus, Loricatosaurus, Sarcolestes, and Lexovisaurus. 

Source:

https://en.wikipedia.org/wiki/Callovosaurus