Dinovember 2016, Day 14

Fancy frill.

Name: Regaliceratops peterhewsi
Meaning: [discoverer] Peter Hews's regal horned face
Time: Late Cretaceous, c 68 million years ago
Place: Alberta
Size: about 5 metres (16.4 feet) long and 1.5-2.5 tonnes (1.7-2.8 tons)
Type of Dinosaur: triceratopsin chasmosaurine (advanced three-horned 'long-frilled' horned dinosaur)

Named in 2015, Regaliceratops is a bit odd for being a very close cousin of the famous Triceratops. Instead of a long, relatively unadorned frill, a short nose horn, and long brow horns, Regaliceratops looks more like a member of the centrosaurine branch of horned dinosaurs, with a big nose horn and tiny brow horns, and a short frill that has large, rounded decorations around the edges. Perhaps Triceratops is part of a lineage that had some more weird members that await discovery.

My drawing of Regaliceratops is a based heavily on a Charles R Knight painting - perhaps my favourite dinosaur painting ever, actually - of a dubious genus of ceratopsian called Agathaumas. Agathaumas remains are almost certainly attributable to Triceratops as well as other dinosaurs, but Knight's highly speculative restoration of this creature is incredibly life-like. The large plated scales, the thick rhinoceros-like neck folds, and the overall presentation of the dinosaur make it seem as though the artist painted it at an easel set up in a Late Cretaceous meadow. Although the restoration was largely speculation, what we know now about horned dinosaur skin makes it seem pretty reasonable. I was struck by the surprising resemblance of the real Regaliceratops when it was announced to Knight's semi-fictitious Agathaumas, and wanted to pay homage to one of the great palaeoart renderings in this Dinovember entry.

Dinovember 2016, Day 4

Leaping Laelaps, 2016 edition.

Name: Dryptosaurus aquilunguis
Meaning: eagle-clawed tearing reptile
Time: Late Cretaceous, c 67 million years ago
Place: New Jersey, possibly North Carolina and elsewhere in the Eastern US
Size: uncertain, but probably around 7.5 metres (25 feet) long
Type of Dinosaur: mysterious tyrannosauroid (tyrant dinosaur) - perhaps an alioramin tyrannosaurine (slender-snouted advanced tyrant dinosaur)

Dryptosaurus - or as it was called at the time, Laelaps, a wonderful name from a mythological hound that was sadly found to be preoccupied by a mite - was one of the first nonavian theropod dinosaurs known to science. In 1896, Charles R Knight, maybe the greatest palaeoartist of them all, painted an iconic image called Leaping Laelaps in which a pair of these animals duke it out - it was one of the first images to portray dinosaurs as the dynamic, active creatures they truly were rather than as dull sluggards, and this painting remains breathtakingly beautiful and exciting even today.

Of course, knowledge of dinosaurs has progressed a lot since 1896. I wanted to revisit Leaping Laelaps and try my hand at restoring it now. Dryptosaurus remains a painfully mysterious dinosaur but evidence points to it being some sort of tyrannosauroid, and an analysis from early this year suggests it may be an alioramin - part of a group of tyrants so far exclusive to Mongolia and China, and known for their slender build and long, narrow skulls with small hornlets along the snout. Not only would Dryptosaurus be geographically unusual if it is an alioramin, what's known of its anatomy is odd too - it has very large, well-developed hand claws, whereas most advanced tyrants were reducing their arms significantly. Certainly an odd duck, Dryptosaurus, and I don't think we can be confident of much until we find more fossils of it - but I've restored it here as a North American alioramin with some serious fingers, while trying to keep the poses faithful to the Knightian original.

There's lots more to say about Dryptosaurus and the dinosaurs of Eastern North America, but that's for another time.