When paleontologists began to unearth Abydosaurus they stumbled upon something of a holy grail as far as sauropods go — the ever-elusive head — and those involved were so cock-a-hoop that they accidentally sawed it in half. However, three more followed, which is astounding given the ease at which sauropod skulls become detached from their neck and crumble to dust so soon after death, not to mention the generous smidgin' of dynamite that was required to loosen the surrounding zircon crystal-fortified rock. Frenzied scrutiny of the first complete, Cretaceous-aged sauropod noggin known from the Americas ensued, and some amazing facts were quick to follow.
Abydosaurus was caught in the act of shifting from primitive chisel-shaped teeth to not quite so primitive peg-like ones which, unlike similar-aged ornithopods with their beaks, cheeks, bone kinesis, and heterodonty, is pretty much the only "improvement" to the basic foliage-croppers that sauropods were blessed with way back when. With a head that accounted for around just 1/200th of body mass (compared to roughly 1/30th in ornithopod dinosaurs and 1/12th in humans) sauropods like Abydosaurus evolved smaller teeth so they could fit more of them in their jaws and thus became more efficient biters. They couldn't chew though because they didn't have cheeks. So huge wads of foliage were swallowed whole instead, and the job of processing plant matter to extract enough go-juice to power an eating machine was undertaken by gastroliths in the gut. This was a big responsibility for lowly rocks.
Apart from the type specimen, three other individuals of Abydosaurus were discovered in the area — DINO 17848, 17849, 39727 — and all have chipped in to give paleontologists a few hints regarding its overall size and family ties. All known Abydosaurus specimens are juveniles which, as adults, would've been middle of the road brachiosaurids size-wise, being somewhat smaller than Giraffatitan (formerly Brachiosaurus brancai) which they most closely resemble. Despite living some 45 million years apart, the skulls of Abydosaurus and the much older Giraffatitan are remarkably similar, but the pair differ in that the latter has substantially broader teeth, while the former has nostrils that are smaller than its eye sockets.
The species epithet, mcintoshi, is a long overdue cap-tip to John S. ("Jack") McIntosh for his contributions to the study of sauropod dinosaurs.
Its Holotype (DINO 16488) is an almost complete skull (500mm long, 250mm high) with the first four neck vertebrae attached.