TEIHIVENATOR

The remains of Teihivenator were initially assigned to the "ostrich mimic" Coelosaurus antiquus by Joseph Leidy in 1865, then Edward Drinker Cope snaffled them to bolster his Laelaps with another species (Laelaps macropus) in 1868 because they were much too big to belong to Coelosaurus. As it turns out, Carl Ludwig Koch has already gifted the name Laelaps to a type of mite (Laelaps agilis) thirty years earlier. So Othniel Charles Marsh announced Dryptosaurus as a replacement in 1877 (in an article footnote describing Titanosaurus montanus, which was itself pre-occupied and eventually renamed Atlantosaurus), much to Cope's chagrin. However, Oliver Perry Hay was the first to publish all known "Laelaps" species under the new generic name Dryptosaurus in 1902, including Dryptosaurus macropus, which, by 1922, William Mathew and Barnum Brown reckoned should've stayed with Leidy's Coelosaurus antiquus. By the by, in 1979 Donald Baird and Jack Horner realised the name Coelosaurus was pre-occupied too, by the battered vertebra of an unknown critter of an uncertain age from somewhere in New Jersey, named in 1854 by an anonymous author who turned out to be Professor Richard Owen.

In 2017, Chan-gyu Yun restudied the fossils of "Dryptosaurus" macropus and announced they belonged to a tyrannosauroid, just like Thomas Holtz had suggested way back in 2004, but the latter considered it dubious, while the former did not. Apparently, "Dryptosaurus" macropus differs from "Coelosaurus" antiquis in features of its shin and in having much more robust toes, and from Dryptosaurus aquilunguis in features of its shin and in being of a smaller size overall. Those differences are as much as could be hoped for, given its scant remains, and warranted awarding "Dryptosaurus" macropus a spangly new name: Teihivenator macropus. However, the author didn't bother with a phylogenetic analysis to determine its affinities "due to the obvious lack of character data". Nor did he make physical copies of his paper available or provide evidence that it was registered with Zoobank within the digital copy, either of which would have satisfied the ICZN's rules of official publication, and perhaps it's just as well.

Yun wrapped up his paper with "the recognition of Teihivenator as a tyrannosauroid calls for a revision of the eastern North American theropod materials to restudy the theropod diversity of Appalachia", and it wasn't long before someone duly obliged. Less than a week after Teihivenator was shunted into the limelight, Chase Brownstein examined its fossils and concluded that it was a chimaera. The toes belong to a derived ornithomimid, the shin to a hitherto unconfirmed tyrannosauroid, and a couple of foot bones could be either or. And on top of that, a large chunk of Yun's "research" allegedly belongs to another author! While all of this is bad news for Teihivenator, it confirms the Appalachian presence of an "ostrich mimic" and a "tyrant lizard" that's neither Dryptosaurus nor Appalachiosaurus. But as it stands, neither owns enough material to justify coining more dinosaur names.