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Dromaeosaur dorsal attacks led to ceratopsian shields and other dino gear? (free pdf)
From: Ben Creisler
A new paper:
Garnet Fraser (2014)
“Bizarre Structures” Point to Dromaeosaurs as Parasites and a New
Theory for the Origin of Avian Flight.
The Journal of Paleontological Sciences: JPS.C.2014.01
Ceratopsian neck frills, lambeosaurine crests, hadrosaur scales,
stegosaur plates, cranial dome horns of Pachycephalosaurus
(=Stygimoloch), diplodocid “whip” tails, sauropod dermal spikes,
elaborate osteoderms, and elongated neural spines are considered
bizarre dinosaur structures. Species identification, thermoregulation,
sexual selection and display functions are theorized to explain these
structures, not mechanically suitable for defense against large
theropods. I propose that bizarre structures may have served to defend
against parasitic dorsal attacks from riding dromaeosaurs. Removal of
soft tissues by dromaeosaurs may have caused desiccation necrosis,
callus formation and osteomyelitis, consistent with deformities in
fossilized bone. Frequent dismounts from large living dinosaurs may
explain the origin of feathers, gliding and avian flight. Plausibility
of dorsal dromaeosaur riding is theorized from extant models
including: the accipitrids (eagles), Geospiza difficilis
septentrionalis (vampire finch), Gulo gulo (wolverine), Isistius sp.
(cookie cutter shark), and vampire bat. Geologist Davidson-Arnott
questions the “lethal sandslide” burial of the Mongolian “fighting
pair,” a Velociraptor and Protoceratops, found locked in battle.
Re-evaluation of their deposition favors a solitary approach to
feeding in dromaeosaurs.