Episode 271 is all about Juravenator, a tiny non-avian juvenile from the same formation as Archaeopteryx.

We also interview Matt Wedel & Brian Engh. Matt Wedel is a vertebrate paleontologist at Western University and co-founder of Sauropod Vertebra Picture of the Week. Brian Engh is a paleoartist and creator of the Jurassic Reimagined. Matt & Brian recently found a well-preserved enormous Brachiosaurus humerus in Utah.

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In this episode, we discuss:

News:

The new spinosaurid, Vallibonavenatrix, was described in Spain source

Two Medicine Dinosaur Center are working on building a 135-ft long animatronic Amphicoelias source

The dinosaur of the day: Juravenator

Coelurosaurian theropod that lived in the Late Jurassic in what is now Bavaria, Germany

Small, bipedal carnivore

Only one juvenile specimen has been found

About 29.5 in (75 cm) long

Adults may have grown another 6 inches

Skull is proportionately large

Had three-pronged claws and serrated teeth

Didn’t have many maxillary teeth (holotype has 8)

Had a short humerus

Had a long fenestra in the skull

May have been nocturnal, based on the scleral rings

May have eaten insects or small lizards

Rare find, and one of the most complete theropods described in Europe

Second non-avian theropod found in the region of Solnhofen

Shows the diversity of predatory dinosaurs in the Late Jurassic in southern Germany

Patch of fossilized skin from the tail has scales and traces of what might be simple feathers

Xu Xing said the scales on the tail may mean there was more variety in feathers of early feathered dinosaurs than in modern birds. Also thought the scales could be a primitive trait, and that Juravenator and other primitive feathered dinosaurs may have had more scales than modern birds

A follow up study of Juravenator supported Xu Xing’s thoughts, and found faint impressions of possibly primitive feathers were on the top of the tail and hips

Another study by Helmut Tischlinger in 2010 looked at the fossils in ultra-violet light, and found more filament-like structures, similar to primitive feathers found on other compsognathids, such as Sinosauropteryx. Also found more patchs of soft tissue on the snout and lower leg, and collagen fibres in the tail vertebrae

Not completely covered by a fluffy feathers (like baby chicks), which may mean that feathers appeared on some parts of the dinosaurs’ bodies before others

Type species: Juravenator starki

Described in 2006 by Ursula Göhlich and Luis Chiappe

Genus name comes from the Jura mountains, where it was found, and venator means “hunter”

Species name in honor of the Stark family, who owns the quarry where it was found

Jura-Museum Eichstätt at Eichstätt had a collecting program from 1989 to 1998 for a nearby quarry. Two volunteers, brothers Klause-Dieter and Hans-Joachim Weiss, found a slab with vertebrate remains. The team found the head of a small theropod, but it was too difficult to extract the fossils. So they did a CT-scan to see if it made sense to dig the rest up. They saw only the neck and part of the lower back and decided not to continue, though the find was reported in 1999. In 2001 there was some publicity around the fossil, which was nicknamed Borsti (a name often given to bristle-haired dogs), because it was thought to have bristly protofeathers. In 2003, the direct of the museum Martina Kölbl-Ebert, decided to finish preparing the fossil. Pino Völkl took 700 hours to prepare the fossil, which had almost the whole articulated skeleton (end of tail is missing) and soft tissues

Originally thought to be part of Compsognathidae, and a close relative of Compsognathus

In 2012, Achim Reisdorf and Michael Wuttke described the taphonomy of Juravenator

Taphonomy: Juravenator specimen may have floated for a short time then sunk to the bottom of the basin after it died. Found in a strange rotated position (the way the pelvis is rotated with respect to the torso). Probably some predation or scavenging of the carcass, but still doesn’t explain the weird rotation

Fun Fact: The five record longest animal humeri are all from Brachiosaurus and Giraffatitan.

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