Episode 63 is all about Concavenator, a carcharodontosaur with quill knobs and a hump back.
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In this episode, we discuss:
- The dinosaur of the day: Concavenator corcovatus
- Theropod, lived in the early Cretaceous
- Type species is Concavenator corcovatus
- Name means “hump backed hunter from Cuenca”
- Fossils were found in 2003
- Named in 2010; paleontologists José Luis Sanz, Francisco Ortega and Fernando Escaso found the fossil
- Holotype is a nearly complete, articulated skeleton (now at the Museo de las Ciencias de Castilla-La Mancha in Spain, and it’s on display)
- Most complete carcharodontosaur, and first to show evidence of feathers or something like feathers
- Most basal Carcharodontosauridae
- Concavenator had small bumps on its forelimbs
- They’re thought to be quill knobs
- In birds, quill knobs anchor the roots of the feathers on their wings
- Other animals with quill knobs on its forelimbs include theropods like Velociraptor
- Scales do not have follicles, and Concavenator‘s bumps have follicular structures, which means Concavenator had quill knobs, and therefore appendages, similar to feathers
- Quill knobs mean it had feathers, or some type of skin structure that was a prequel to feathers
- Before Concavenator, fossils from coelurosaurs (a theropod group with feathers) showed that birds evolved from dinosaurs; but Concavenator was a carcharodontosaurid not a coelurosaur; its last shared common ancestor with coelurosaurs was in the Middle Jurassic. Concavenator’s quill knobs was the first evidence of a theropod dinosaurs outside the coelurosaur group covered in something other than scales
- Back in 2010, showed that feathers were more widespread among theropods than scientists had thought, and that feathers could appear on larger dinosaurs and not cover an entire body
- Luis Chiappe, director of The Dinosaur Institute at the Natural Museum of LA County, told Discovery News in 2010 that Concavenator “shows that feathers were not restricted to just small dinosaurs, even if they didn’t have to cover their entire bodies. This fossil offers additional support documenting the dinosaurian ancestry of birds and the claim that birds are living dinosaurs.”
- May have had some sparse protofeathers on its lower arms (but no feathers found with the fossils, so not entirely sure it was feathers)
- Feathers or feather structures may have helped with thermal control, or helped with aerodynamics
- Since the quill knobs are only on the forearms, they were probably used for display
- Not everyone believes these are actually quill knobs. Darren Naish said these bumps were irregularly spaced, and that many animals have something similar along their intermuscular lines (they were muscular insertion points)
- Elana Cuesta, Ortega and Sanz (who described Concavenator in 2010) studied the bumps again and presented their findings at the 2015 meeting of the Society of Vertebrate Paleontology, where they concluded that the bumps were quill knobs, though it was unusual for them to be on the top surface of the bone. However, this can be seen in some modern birds, such as the Moorhen
- Also found impressions that show it had wide, rectangular scales under its tail and feet
- Also notable: two tall vertebrae in front of the hips formed a tall, narrow, pointed crest (possibly had a hump) on the back
- Had a short, but tall sail or hump that was only on its lower back (looked like a dorsal fin)
- Francisco Ortega has said the hump may have looked similar to humps we see on some modern cows
- Tall neural spines have been found in spinosaurids, carcharodontosaurids and some tetanurans before, but not only on the lower back. Concavenator’s back hump function is unclear, since it is so short
- Hump or sail on its lower back (above the hips) may have been used for display, thermoregulation, or to store fat or something else
- Becklespinax has been compared to Concavenator and some scientists think they could be the same genera (they are similar in size, look alike; have the hump); but hard to know, since Becklespinax all we know is 3 dorsal vertebrae; also Becklespinax is 10 million years older
- About 20 ft (6 m) long
- Nearly complete skull
- Short, stout claws
- Lived in wetlands
- Concavenator shows that carcharadontosaurids lived in Europe and the northern continents, in addition to South America, Africa and Australia
- Carcharodontosaurids (name means “shark-toothed lizards) were carnivorous theropods
- Ernst Stromer named the family in 1931
- Family includes Giganotosaurus, Mapusaurus, Carcharodontosaurus, and Tyrannotitan (all about same size or larger than T-rex)
- Carcharodontosaurids and spinosaurids were the largest predators in Gondwana in the early and middle Cretaceous
- Fun Fact: Partly from the “introduction on taxonomy” in wikiversity.org: There are many naming convention suffixes for taxonomy (groups like Kingdom, Phylum, Class, Order, Family, Genus, Species) (and we often quote research that uses them a lot). The two most common seem to be: groups of families (superfamily)–oidea (often shortened to “oid”), family–idea (often shortened to “id”). Superfamilies are especially useful because most dinosaurs have a unique genus and taking T-rex, for example, talking about the family (Tyrannosauridae) leaves out a lot of similar dinosaurs while going up to the order Saurischia (or even suborder theropoda) is often too broad. Plus it helps reduce arguments about which specific family a genus is in; and instead we can just talk about their characteristics.
