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.

Dinovember 2016, Day 2

Don't let the nubby arms fool you, abelisaurs are all business.

Name: Pycnonemosaurus nevesi
Meaning: Neves's thick forest reptile [after the Brazilian state of Mato Grosso, 'thick forest', where it was found]
Time: Late Cretaceous, c 70 million years ago
Place: Southwest Brazil
Size: about 8.6-9.1 metres (28-30 feet) long
Type of Dinosaur: brachyrostran abelisaurid (blunt-faced, stump-armed predatory dinosaur)

The abelisaurs were one of the dominant group of predators on the southern continents during the Cretaceous Period. Many types of abelisaurs are known, mainly from only partial remains, so estimating the body size of these animals has been contentious. A study from this year used methods consistent across all abelisaurs to estimate size, and the results found that Pycnonemosaurus has claimed the crown as the biggest of these southern killers yet known.

Abelisaurs have famously stumpy, practically vestigial arms - that could be rotated totally at the shoulder, like our own arms. It seems that these reduced limbs could have functioned as display devices, which is why I applied a bold tissue fan to the arm-nubs of the king of the abelisaurs in the portrait above.

Day of the Diplodocids Redux

And he means business -- just check out that switchblade comb.
[by the author]

Remember Tschopp et al 2015? You know the paper... Brontosaurus is back! Huzzah and tally-ho and all that. I wrote about it here, nearly 15 months ago. I'm bringing it back up now because it will be relevant to a post that I've had in the works for a little while now. That should hopefully materialise here within the next little while but before it does, let's look back at good ol' Brontosaurus and see what was really important about its resurrection from the open grave of taxonomic obsolescence...

Day of the Diplodocids

Welcome, true believers, to a Very Special installment of Noah's Ravens. As you have no doubt seen while scrolling through Facebook or Twitter or while idly surfing the web, yesterday marked the appearance of a new (very long) paper reviewing the diplodocid sauropods, 'A specimen-level phylogenetic analysis and taxonomic revision of Diplodocidae (Dinosauria, Sauropoda)' by Emanuel Tschopp, Octávio Mateus, and Roger B J Benson, published open-access in PeerJ. Although I'm certain you've all had time to read it, pore lovingly over the cladograms, savour each and every word about each and every specimen, and completely lose yourself in the figures depicting small chunks of bone, I thought it might be nice to have a brief(ish) round-up post that covers some of the big ideas of the paper in a condensed(ish), hopefully-easy(ish) read.

It was nice knowing you, Diplodocus longus, but all good things
must come to an end. Read on to find out why. Legs belonging to
The Sauropod Formerly Known As Diplodocus longus at centre.
[photograph by the author]