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.

Frederic Loomis Discovers Everything, Episode 1: Raiders of the Lost Continent

Around three million years ago, South America became connected to North America via the Isthmus of Panama, and an event called the Great American Biotic Interchange took place, where wildlife from South America moved north and vice versa. Prior to this, South America had been isolated from most of the rest of the world since the Cretaceous Period, and connected only to Antarctica until they separated about 30 million years ago, allowing little exchange of wildlife from other places in world. As such, South America was a 'lost continent,' a strange land cut off almost completely from the rest of the world, with its own array of unique organisms, the characters in their own isolated evolutionary story. It was into this strange world that the North American emigrants came some three million years ago, and it was into the fossil echoes of this world that a very different group of North Americans came in the early 20th century.

Some Patagonian fossils from the Cenozoic Era. They include notoungulates (top row
and left middle row) such as the sheep-sized digger Mesotherium (top centre), superficially
elephantine astrapotheres (lower jaw of Parastrapotherium, middle right), and the extant
xenarthrans (bottom row), including the flattened armour of an armadillo.
[photograph by the author]

'Footmarks On Stone,' or, Why This Blog Is Called Noah's Ravens

The year is 1802. In South Hadley, Massachusetts, a farmer called Pliny Moody discovers something strange in a slab of rock. Closer investigation seems to indicate that the unusual markings in the rock are footprints, with three narrow, spread-out toes, very similar to the footprints of birds.

The mysterious track-maker was referred to as 'Noah's Raven,' in reference to the first bird set out from the ark after the flood in the book of Genesis; presumably these footprints were thought to have been made by the raven, which flew 'back and forth until the water had dried up from the earth,' and, apparently, eventually came to land in western Massachusetts.

The 'Noah's Raven' specimen at the Beneski. [photograph by the author]