Episode 248 is all about Polacanthus, an ankylosaur that was described in the 1800s, but no one is sure who named it.

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In this episode, we discuss:

News:

• After decades of being classified as Massospondylus, “grey skull” has a new name, Ngwevu intloko source
• Mission Jurassic in North Wyoming could hold over 100 dinosaurs in one square mile source
• A group of juvenile hadrosaurs was found at Pipestone Creek, near the Philip J. Currie Museum source
• The Scottish government is working on better protecting the fossils on the Isle of Skye in Scotland source
• In India, a group of scientists are pushing for a bill that will designate and safeguard fossil sites source
• In Romania, new dinosaur nests have been found, most likely from a hadrosaur like Telmatosaurus source
• The Natural History Museum in London has digitized their holotype of Mantellisaurus source
• The Central Museum of Mongolian Dinosaurs recently opened a new exhibition hall, themed Paleozoic Era source
• Dinosaur Park in Laurel, Maryland has an open house this summer, on September 7 source
• Trix the T.rex is back in Leiden, at the updated Naturalis Biodiversity Center in the Netherlands source
• A new project called “On the Trail of Dinosaurs,” will bring the Dinosaur Tracks from the Australian Dampier Peninsula to life source
• children visiting the North Carolina Museum of Natural Sciences regularly try to help the injured sauropod, giving it hugs and Band-Aids. source
• South Dakota rancher Kenny Brown recently retired and bequeathed his 1,330 acre ranch to the School of Mines source
• PLOS One blog has a list of events for National Fossil Day in the US (October 16) source
• On August 29, the US Postal Service is issuing four new T. rex stamps, with a holographs source
• Nickelodeon has a new animated series coming out September 14, LEGO Jurassic World: Legend of Isla Nubar source

The dinosaur of the day: Polacanthus

• Ankylosaur that lived in the Early Cretaceous in what is now England (Upper Wessex Formation)
• Quadrupedal ornithischian
• Not well known (especially the skull)
• Estimated to be about 16 ft (5 m) long
• Gregory Paul estimated it to weigh 2 tonnes
• Had relatively long hindlimbs
• Body had armor plates and spikes
• Had a large pelvic or sacral shield (bone over the hips). The holotype has four rows of larger osteoderms on the side, with smaller ossicles
• John Whitaker Hulke in the late 1800s suggested the tail had two rows of osteoderms on each side
• Franz Nopcsa in 1905 thought the tail and front of the body had two parallel rows of spikes, one on each side
• Wiliam T Blows in 1987 mostly agreed with Nopcsa but said there were three spike types
• Type species: Polacanthus foxii
• Found in 1865 on the Isle of Wight by Reverend William Fox
• Genus means “many thorns” or “many prickles”
• The genus name refers to the spikes on its armor
• The species name refers to Fox
• Fox at first was going to have his friend Alfred Tennyson name the dinosaur. Tennyson suggested naming it Euacanthus vectianus but this wasn’t accepted
• Fox mentioned the find in a lecture to the British Association, and let Richard Owen name it Polacanthus foxii
• The Illustrated London News printed an anonymous article with Fox’s lecture but there’s no corresponding publication by Owen
• Some people think that Thomas Huxley named the dinosaur, others think it was Owen, Fox, or someone anonymous
• Holotype consists of an incomplete skeleton (includes vertebrae, sacrum, most of the pelvis, most of the left hindleg, ribs, chevrons, ossified tendons, and spikes)
• Early illustrations gave it a generic head (only knew the back half)
• John Whitaker Hulke published the first description of the dinosaur in 1881, and said it had deteriorated over the years (the armor had mostly fallen apart). But then Fox died (same year), and his fossils were acquired by the British Museum of Natural History. Caleb Barlow reassembled Polacanthus, even though Hulke thought it couldn’t be done
• Hulke redescribed Polacanthus in 1887, focusing on the armor
• Then in 1905, Franz Nopcsa described Polacanthus and illustrated the spikes
• Other possible specimens included two found in 1843 by John Edward Lee
• More have been referred, and they include parts of the armor or single bones
• Wiliam T Blows exacavated a second partial skeleton (with parts of the skull) in 1979. Parts of it had been removed since 1876
• Many species have been named but only one species is considered to be valid now
• Other species names include Polacanthus becklesi (now considered to be a junior synonym), Polacanthus marshi (Blows claimed in 1987 that Hoplitosaurus was Polacanthus marshi, but this has now been rejected), Polacanthus rudgwickensis (named by Blows in 1996 aftering reviewing fossils found in 1985 thought to be Iguanodon, it’s about 30% longer than Polacanthus foxii but in 2015 Blows named it as a separate genus, Horshamosaurus)
• Also, Polacanthus ponderosus (Nopcsa named in 1928 based on a left scapula that Gideon Mantell had thought was Hylaeosaurus, as well as a tibia and humerus from another specimen, but it turns out the tibia and humerus were found on Wight, and are casts, while the scapula was from Bolney)
• Walter Coombs renamed Polacanthus foxii to Hylaeosaurus foxi in 1971, but this has not been accepted
• Some people have thought Polacanthus was the same as Hylaeosaurus armatus, but Blows rejected that in 1987 based on age and anatomical differences

Fun Fact: There is new evidence that some theropods in Mongolia laid eggs in groups at nesting sites.