The ankylosaurus, already the best dinosaur, has been further improved. Spicomellus afer, sporting what the BBC describes as "punk rock" dermal armor along its head and back, is at 165m years the oldest example of the family. Though previously known from scant fossils, a complete set reveals a full set of liberty spikes.
As described in the paper Extreme armour in the world's oldest ankylosaur, published in Nature…
Here we describe a new, much more complete specimen that confirms the ankylosaurian affinities of Spicomellus, and demonstrates that it has uniquely elaborate dermal armour unlike that of any other vertebrate, extant or extinct. The presence of 'handle' vertebrae in the tail of Spicomellus indicates that it possessed a tail weapon, overturning current understanding of tail club evolution in ankylosaurs, as these structures were previously thought to have evolved only in the Early Cretaceous4. This ornate armour may have functioned for display as well as defence, and a later reduction to simpler armour with less extravagant osteoderms in Late Cretaceous taxa might indicate a shift towards a primarily defensive function, perhaps in response to increased predation pressures or a switch to combative courtship displays.
The discovery may upend what's understood about Ankylosaur evolution. Instead of becoming more elaborate and spiky as giant carnivores evolved later in the Cretaceous, it now appears that spikes were a display adaptation and the presence of big trouble led their armor to become sleeker and simpler over time.
Prof Butler's project co-leader, Prof Susannah Maidment of the Natural History Museum, added that it was surprising that the spikes were fused directly on to the bone.
"We don't see that in any other animal, living or extinct," she said.
"It's absolutely covered in really weird spikes and protrusions all over the back of the animal, including a bony collar that wraps around its neck and some sort of weapon on the end of its tail, so a most unusual dinosaur," she said.
I looked up the artist commissioned by the researchers, Matt Dempsey, and it turns out he has an excellent website.
Introducing a crazy new look for Spicomellus, based on new osteoderms unlike anything we've ever seen before. I was brought in to produce a life reconstruction based on the new material, published today in Nature by Maidment et al:
