Say hello to Falcarius utahensis.
This creature was becoming a herbivore (plant-eater), but fossils described in today’s Nature indicate his (or her) ancestors were most definitely carnivorous (meat-eaters).
The story can be read on-line here. Here’s the significant “bite”:
Caught in the act of evolution, the odd-looking, feathered dinosaur was becoming more vegetarian, moving away from its meat-eating ancestors.
It had the built-for-speed legs of meat-eaters, but was developing the bigger belly of plant-eaters. It had already lost the serrated teeth needed for tearing flesh. Those were replaced with the smaller, duller vegetarian variety.
‘I doubt seriously this animal could cut a steak with that mouth,’ said Utah state paleontologist James Kirkland, one of those who discovered the bones of the beast in east-central Utah.
This relates to the never-ending creationism saga in several ways, including one that shows an important distinction between Evolution and Creationism:
Creationists insist that, if creatures changed their eating habits in the past, it was from herbivores (before the Fall, when the Creation was Good) to carnivores (after the Fall, and the introduction of sin and death into the world).
I should mention that I went to New Mexico Tech with the discoverer, Dr. Jim “Boston” Kirkland, during the late 70’s.
Back in the day, between beer bashes and band gigs and classes, we even managed to get in some good field trips to the Glass Mountains of Texas, the Bisti Badlands of New Mexico, and more.
But, I digress. What features of the find indicate its transition from carnivore to herbivore? The AP article mentions this:
It ate plants, but its bones show the transition from its carnivorous ancestors while still in progress.
All plant-eating dinosaurs were ultimately descended from a meat-eater, and switchovers to plant-eating occurred several times. The newly discovered species, which lived 125 million years ago, could help scientists understand details of how the changeovers took place.
It’s ‘our first really good case of a dinosaur in the midst of shifting from the meat-eating body to a plant-eating one,’ said an expert not involved in the discovery, Thomas R. Holtz Jr. of the University of Maryland.
‘It’s definitely eating a substantial amount of plants, (but) we still see the original imprint of meat-eating upon it.’
The find will be presented in Thursday’s Nature. The AP article also mentions that
… analysis revealed that Falcarius was the earliest known member of a bizarre-looking group of plant-eaters called therizinosaurs (pronounced THAY-rih-ZY-no-sores.) Found mostly in Asia, the barrel-bodied creatures waddled upright like Godzilla or ‘a pot-bellied bear,’ Kirkland said.
Falcarius, very early in its evolution into the therizinosaur body type, retained the rather horizontal posture and powerful legs of its meat-eating ancestors. And its teeth were more suited for eating plants, [Utah scientist Lindsay] Zanno said.
It also showed some change toward the larger gut needed to digest plant material rather than meat, as well as a lengthened neck and smaller head associated with eating plants, she said.
Holtz said Falcarius still had fairly slender proportions overall rather than the barrel body of later therizinosaurs. ‘This one could probably move fairly quickly,’ he said, whereas its more evolved relatives ‘would have had problems hunting things faster than a tree.’
Kirkland and Zanno said they suspect Falcarius probably ate some meat in addition to plants.
‘I wouldn’t doubt this thing would eat a lizard or two in a pinch,’ Kirkland said.
The Nature article has some more “meat” to it:
The creature’s teeth have a shape that seems to be adapted to leaf shredding, the researchers report. Similar teeth can be found in modern iguanas, for example, a reptilian family that also has a varied diet.
Falcarius utahensis also has a slightly widened pelvis, Kirkland’s team points out, which would have been necessary to accommodate the longer gut needed to extract nutrients from plants.
But the dinosaur’s legs reveal that it still has adaptations suited for meat eating as well. The creature’s thigh bones were longer than its shin bones, suggesting that it could run at an impressive pace. “The legs are still adapted for running after prey,” says Kirkland. Later therizinosauroids have longer shin bones, which suggests that they waddled around like long-legged birds.
The real nitty-gritty is in the Nature paper itself, of course. A sample:
The dentary teeth share several features with the teeth of other therizinosauroids (Fig. 2). Similarities include posteriorly small, lanceolate and basally constricted crowns that become taller anteriorly, as well as the presence of inflated, circular roots. … A phylogenetic analysis (Fig. 3) provides strong support for the hypothesis that Falcarius is the basalmost therizinosauroid known.
Translation: yes, this creature really is related to the plant-eating therizinosauroids which came later. It is a transitional fossil!
And there we have it - a real test of Creation versus Evolution!
The standard creationist claim that all creatures were originally vegetarian appears all over the web. Here is one example:
The Bible teaches the following. People and animals alike were given plants to eat in the beginning (Genesis 1:29–30). There was no meat-eating before the Fall, whether by man or by animal. The carnivorous part of the present ‘food chain’ did not exist. And God appropriately described His creation as ‘very good’ (Genesis 1:31).…
As mentioned already here at the Thumb, Steve said
the week won’t end without Answers In Genesis claiming that it somehow destroys evolution and confirms creationism.
A good prediction! I’ll wager that claim will involve this observation from the AP article:
Bones from hundreds or maybe thousands of these dinosaurs were discovered at a two-acre dig site in east-central Utah, south of the town of Green River. Nobody knows why they gathered there or what killed them, Kirkland said.
I’ll bet a virtual brew that Answers in Genesis will be touting this as evidence of “The Great World-wide Flood,” while conveniently overlooking that sticky point about some dinosaurs becoming herbivores after the Fall, contrary to Scripture.
I’m inviting Prof. Steve Steve to break away from Kansas to visit New Mexico later this summer, and collaborate with me on the Definitive Proof that there ain’t no way the Fossil Record is compatible with a single, Noachian deluge. But that will be down the road a month or two. Come on down, Prof. Steve Steve!
As always, please observe the Panda’s Thumb Comment Integrity policy. (In other words, Play nice, people! And stay on topic!)