February 18th

1928 – John Ostrom Born

On this day in dinosaurs, we remember the contributions of John Ostrom–his struggle and those who took the steps to make his once-outlandish notions into mainstream scientific thought.

John Ostrom and Deinonychus
John Ostrom / Wikimedia Commons

He may be most famous for giving the world Deinonychus, but John Ostrom’s biggest contributions to science were his ideas about warm-blooded dinosaurs and the evolutionary links between non-avian dinosaurs and modern-day birds.

Ostrom was one of those who kickstarted the “Dinosaur Renaissance” and brought new ideas to the science of paleontology that are still reverberating through the field today. He was one of the first to postulate dinosaurs moving in herds from trackways and also contributed significant studies on Archaeopteryx. In his later years, he watched a flurry of feathered dinosaurs emerge from China, further vindicating his hypotheses from decades earlier.

 

1839 – Harry Seeley Born

Today, we also celebrate the birthday of the man who classified dinosaurs into two major groups: Saurischians and Ornithischians. The “lizard-hipped” and “bird-hipped” dinosaurs, respectively, were named by Seeley for their way their hips resembled those of modern animals.

Harry Seeley / Wikimedia Commons
Harry Seeley / Wikimedia Commons

Until the development of cladistic analyses in the 1980s, paleontologists could not even conclusively state that all dinosaurs had a common ancestor. We also recognize that, somewhat confusingly, “bird-hipped” dinosaurs did not evolve into birds. The “lizard-hipped” saurischians include sauropods and theropods–the group most closely related to modern birds.

Classifications are always hotly contested in the scientific community, so for Seeley’s system to stand since he proposed it in 1888 is a major achievement.
Share photos with dinosaurs that would make Seeley and Ostrom smile! Post your photos on Facebook and Twitter using the hashtag #TDIDinos.

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