Gerhard Heilmann

From EvoWiki

Gerhard Heilmann was a Danish artist and scientist profoundly interested in the origins and phylogeny of birds. His seminal 1926 work, The Origin of Birds was as close as scientific work can be to canon, and reigned more or less unchallenged as the principle tome on the matter, until the late 1960s.

Heilmann considered theropod dinosaurs and Aves to be closely related, to the point where he could reject theropod ancestry on only the grounds of a singular anatomical feature: the clavicles. Clavicles fuse in birds to form the furcula, and at the time that Heilmann carried out his research, theropod fossils lacked clavicles altogether, or were characterized by clavicle reduction. To Heilmann, this precluded theropods from avian ancestry. He suggested that "pseudosuchian thecodonts" gave rise to birds, such as Riojasuchus, or Ornithosuchus. His work was heavily influenced by that of famous South African paleontologist Robert Broom and his 1913 description of Euparkeria capensis. Heilmann's hypothesis, incorrect, was largely a function of an overly strict interpretation of Dollo's Law, and the poor theropod fossil record of the day. Despite the errors in his conclusions, Heilmann's 1926 study is still considered a classic.