Show transcript:

Hi. If you’re hearing this, it means I’m sick or something else has happened that has kept me from making a new episode this week. This was a Patreon bonus episode from mid-August 2019. I think it’s a good one. If you’re a Patreon subscriber, I’m sorry you don’t have a new episode to listen to this time. Hopefully I’ll be feeling better soon and we can get back to learning about lots of strange animals.

Welcome to the Patreon bonus episode of Strange Animals Podcast for mid-August, 2019!

While I was doing research for the paleontology mistakes and frauds episodes, I came across the discovery of what might have been the biggest land animal that ever lived. But while I wanted to include it in one episode or the other, it wasn’t clear that it was either a mistake or a fraud. It might in fact have been a real discovery, now lost.

In late 1877 or early 1878, a man named Oramel Lucas was digging up dinosaur bones for the famous paleontologist Edward Cope. Cope was one of the men we talked about in the paleontological mistakes episode, the bitter enemy of Othniel Marsh. Lucas directed a team of workers digging for fossils in a number of sites near Garden Park in Colorado, and around the summer of 1878 he shipped the fossils he’d found to Marsh. Among them was a partial neural arch of a sauropod.

The neural arch is the top part of a vertebra, in this case probably one near the hip. Sauropods, of course, are the biggest land animals known. Brontosaurus, Apatosaurus, and Diplodocus are all sauropods. Sauropods had long necks that were probably mostly held horizontally as the animal cropped low-growing plants and shrubs, and extremely long tails held off the ground. Their legs were column-like, something like enormous elephant legs, to support the massively heavy body.

We know what Diplodocus looked like because we have lots of Diplodocus fossils and can reconstruct the entire skeleton, but for most other sauropods we still only have partial skeletons. The body size and shape of other sauropods are conjecture based on what we know about Diplodocus. In some cases we only have a few bones, or in the case of Cope’s 1878 sauropod, a single partial bone.

Cope examined the neural arch, sketched it and made notes, and published a formal description of it later in 1878. He named it Amphicoelias [Am-fi-sil-i-as] fragillimus.

The largest species of Diplodocus, D. hallorum, was about 108 feet long, or 33 meters, measuring from its stretched-out head to the tip of its tail. Estimates of fragillimus from Cope’s measurement of the single neural arch suggest that its tail alone might be longer than Diplodocus’s whole body.

Cope measured fragillimus’s partial neural arch as 1.5 meters tall, or almost five feet. That’s only the part that remained. It was broken and weathered, but the entire vertebra may have been as large as 2.7 meters high, or 8.85 feet. From that measurement, and considering that fragillimus was seemingly related to Diplodocus, even the most conservative estimate of fragillimus’s overall size is 40 meters long, or 131 feet, and could be as long as 60 meters, or 197 feet. This is far larger than even Seismosaurus, which is estimated to have grown 33.5 meters long, or 110 feet, and which is considered the largest land animal known.

So why isn’t fragillimus considered the largest land animal known? Mainly because we no longer have the fossil to study. It’s completely gone with no indication of where it might be or what happened to it. And that has led to some people thinking that it either never existed in the first place, or that Cope measured it wrong.

One argument is that Cope wrote down the measurements wrong and that the neural arch wasn’t nearly as large as Cope’s notes indicate. But Lucas, who collected the fossil, always made his own measurements and these match up with what Cope reported. Lucas and Cope both remarked on the size of the fossil,