In 1976, Thulborn joined Dr Mary Wade and a team of volunteers to excavate the
Lark Quarry dinosaur tracksite, located near
Winton, Queensland. Their work uncovered what remains the world’s only known evidence of a dinosaur stampede, published in 1984, which captivated scientists and the public alike. He later critically reassessed these findings in
Lark Quarry Revisited (2013), demonstrating rigorous methods in ichnological interpretation. His work helped secure the site’s inclusion on the
Australian National Heritage List in 2004, ensuring its preservation for research and public education. In 1982, Thulborn debunked the purported plesiosaur embryos discovered by
Harry Govier Seeley. Thulborn concluded that Seeley's supposed embryos were actually nodules of
mudstone and
shale derived from sediments that once filled in a
crustacean burrow system and were not even animal body fossils. Thulborn’s research also included dinosaur locomotion, thermoregulation, tooth wear, jaw action, reproduction, and palaeobiology across diverse taxa. He investigated the evolutionary relationships of birds and theropods, including studies on
Archaeopteryx, digit homology, and flight mechanics. Thulborn also made important contributions to understanding Australia’s prehistoric vertebrate diversity, including mammal-like reptiles, dicynodonts, Triassic vertebrate faunas, plesiosaurs, and coprolites. His critical approach and publications influenced both Australian and international palaeontology. ==Honours==