With four new dinosaur species announced from South America this October, this might be the happiest Halloween for fossil aficionados since 2015, when the giant dromaeosaur Dakotaraptor was announced on October 30th. Though Dakotaraptor arguably had the better timing, the announcement of the carnivorous Spectrovenator ragei on October 14th this year delivers one of the coolest, most Halloweeny dinosaur names to date (well, except for Zuul maybe). More importantly, it fills major gaps in our knowledge of a freakish line of carnivorous dinosaurs, the abelisaurids.
According to the description, Spectrovenator means “Ghost Hunter.” Unlike many other dinosaurs with creepy names (Zuul, Thanos, or Xingtianosaurus—named for a headless warrior from Chinese mythology), Spectrovenator isn’t making a cultural reference. Instead, the ghost part of the name refers to its unexpected discovery in jackets taken for a recently discovered titanosaur sauropod species, Tapuiasaurus, evoking a ghost-like come-outta-nowhere appearance. The hunter part simply refers to its presumed predatory nature. So instead of “Ghost Hunter” in the sense of a hunter of ghosts, its name mainly means that it is a hunter that is ghostly.
Spectrovenator’s species name refers to Dr Jean-Claude Rage. Since’ it’s French, it’s probably pronounced rah-ZHAY, but with a name like Spectrovenator, I find I want to pronounce it RAGE-y. ‘Cause, y’know, it’s a carnivore, so it could go into a rage, right? Then again, if it died in the grip of a powerful rage, maybe it carries some sort of prehistoric Ju-On sort of Grudge . . . naaaaaah.
Scientifically speaking, though, Spectrovenator will play in important role in future studies. Though it’s an abelisaurid, it doesn’t come from Late Cretaceous rocks like the others; nor does it spring from Jurassic rocks like the oldest known predecessor of the group, Eoabelisaurus. Gaps in phylogenies (an evolutionary family tree, so to speak) spanning tens of millions of years long like that have earned the moniker “ghost lineage.” Appropriately enough, the Ghost Hunter comes from Early Cretaceous rocks, splitting and narrowing down the abelisaur ghost lineage. It ain’t afraid of no ghost lineages!
Better yet, the Spectrovenator holotype came with such a beautifully preserved skull that even Yorick would be jealous. Abelisaurs in general have highly specialized, bizarre skulls that set them apart from other large meat-eating dinosaur groups; Carnotaurus’ skull even sports oddly-shaped horns, an extreme rarity among carnivorous tetrapods. Spectrovenator displays many of the characteristic features of abelisaurs, though it lacks some as well, like the joint in the middle of the jaw. This suggests Spectrovenator didn’t have as specialized a bite as its later kin. Moreover, its skull sports some ceratosaurid features, making it a missing link of sorts for one of the weirdest families of dinosaur carnivores. This thing is a treasure trove of data that will answer many questions in the years to come, perhaps even helping us deduce just what the abelisaurs did with their specialized bite.
A less prominent specialization among abelisaurs shows up in Spectrovenator as well. Special fins of bone jutting from their tail vertebrae lent extra attachment area for enlarged caudofemoralis muscles. These muscles run along the tail, ultimately anchored to the back of the femur and pulling it back, providing it with great sprinting speed. When attacking, it could move faster than Ecto-1 speeding off to the Sedgewick Hotel!