Impact of discovery of Segisaurus on Gerhard Heilmann's book on avian origins

[VD231991]

In his 1926 book The Origin of Birds, Gerhard Heilmann argued that birds could not have evolved from dinosaurs and instead must have descended from an exotic type of thecodont because he noted that many dinosaur fossils discovered at the time lacked the furcula of birds, opining that Thomas Huxley's hypothesis about birds being descendants of theropod dinosaurs ran counter to Dollo's law by implying that if theropods were bird ancestors, then birds could not have developed the furcula once it was lost in theropods. However, the discovery of the theropod Segisaurus from the Early Jurassic of Arizona in the 1930s undermined Heilmann's hypothesis of bird origins because the type species of Segisaurus was the first-ever non-avian theropod specimen to be discovered with a furcula. Were a handful of paleontologists and ornithologists prior to John Ostrom in the 1940s and 1950s inclined to consider Huxley's theory of a dinosaurian origin for birds more probable than Heilmann's case for birds being descended from non-dinosaurian thecodonts after reading the fine text of the Segisaurus paper with respect to the occurrence of a furcula in Segisaurus?

[Funk]

Well, according to the Wikipedia article, the furcula was only identified as such in 2005 (was identified as clavicles before), so it could obviously not have had any impact before that.

[VD231991]

Well, according to the Wikipedia article, the furcula was only identified as such in 2005 (was identified as clavicles before), so it could obviously not have had any impact before that.

I didn't know that the 2005 paper by Matthew Carrano and colleagues recognized the presence of a furcula in Segisaurus for the first time, but the 1997 book Encyclopedia of Dinosaurs notes in a number of encyclopedic entries that a handful of non-paravian tetanuran taxa also have furculae. The presence of clavicles in Segisaurus led Charles Lewis Camp (who published the paper describing Segisaurus in 1936) to erroneously believe that those clavicles supported a patagium along the neck like that of flying dragons.