Ancient bird becomes second Australian species to be named from the Cretaceous period

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: A pair of exceptionally rare Cretaceous bird bones found at separate sites near Richmond, Queensland, reveal a previously unknown species—the second formally named Cretaceous bird from Australia. Cretaceous bird fossils are extremely scarce in Australia, with fewer than a dozen isolated bones reported, making these finds especially significant.

The research is published in the Journal of Vertebrate Paleontology. Kevin Petersen, a former curator of Kronosaurus Korner, discovered the first bone while fossil hunting in the public collecting areas near Richmond. While excavating the "fish mash layer"—a fossil-rich stratum packed with fish remains and scattered teeth from marine predators like plesiosaurs and ichthyosaurs—Petersen noticed a long, light-brown bone unlike any I'd seen before.

He set it aside for later identification. A week later, after rain, Petersen found a second unfamiliar bone on a rock slab. He photographed both specimens and sent the images to Dr.

Matt White (University of New England). "I recognized them immediately as bird bones," White said. "These specimens are especially significant because so few have been found in Australia, and none were directly comparable until now." White identified one element as a tarsometatarsus (the fused foot bones of birds) and the other as a tibiotarsus.

Both were well preserved but partly encased in concretion, so the team opted not to fully excavate them. The specimens were scanned at the Australian Nuclear Science and Technology Organisation (ANSTO) by Dr. White converted the scan data into 3D meshes to visualize the bones within the rock.

This nondestructive imaging allowed direct comparison between the new tibiotarsus and Nanantius eos—the only other formally named Cretaceous bird from Australia, described in 1986. The scans revealed clear anatomical differences. The new taxon has been named Tenuicruris piscanexum: Tenuicruris ("slender leg") refers to the gracile limb morphology, and piscanexum links the species to the fish-rich layer in which it was found.