Dinosaur-eating Mammals (You heard me right): Jeff Hecht at New Scientist has a good write-up of the discovery of a dog-sized 130-million year old mammal with dinosaur bones in its gut. Most mammals may have been humble little critters during the Age of the Dinosaurs, but at least a few seemed to have turned the tables.
More like this
When I was first becoming acquainted with dinosaurs during the latter half of the 1980's, the standard "rule" for theropod dinosaurs was that as they grew bigger through the course of time their heads became more robust and their arms grew smaller. Just comparing the Jurassic predator Allosaurus…
Maybe it's because I write too much, but I am frequently surprised and sometimes a little freaked out at the strange coincidences that have so often cropped up during my time here at Tet Zoo. Long-time readers will recall the several occasions when we've looked at hypothetical intelligent…
This past fall my friends Julia and Neil were kind enough to obtain a signed copy of the new book Evolution: What the Fossils Say and Why It Matters for me from the annual SVP meeting. Although I had not heard of the author, Dr. Donald Prothero, prior to reading the book I was certainly impressed…
So, if you read the previous article, you'll know that we're here because Tet Zoo was four years old on January 21st. In that article, I got as far as discussing blog-relevant events that happened up to the end of May or so. Time to crack on...
During June I had a particularly bizarre job - I did…
Dinosaur meat...tastes like chicken?
Sort of the reverse of a Komodo dragon (http://www.isidore-of-seville.com/komodo/). I wonder if the dinosaurs called it the "Komodo dog"...
That was the Age of the Dinovores.
It strikes me that this is surprising only because we have traditionally used political metaphors in biology. As if Linnaeus' Kingdom, class, order metaphors (he also had "phalanx" but that didn't survive) weren't enough, we have since Cuvier spoken of the "age in which X ruled". Dinosaurs didn't rule their "age" - they just happened to be larger than everything else.
So why would we expect that an entire group like mammals, which are as long-standing as dinosaurs and their offspring the birds, would be any less ecologically diverse than they are? Why is it surprising that mammals were carnivores and predators, than if they were insectivores or ovivores or herbivores? Only because carnivores are the "political heads" of biology, and this was the Age of Dinosaurs...
Well, and only because previous finds of carnivorous mammals of this size and age have apparently been pretty rare. While it's importatnt to be continually willing to reevaluate one's operating assumptions when new evidence comes along, it's pretty difficult to go through life without operating upon assumptions reasonably based upon the data previously available.
I agree with Dr. Wilkins. I listened to a story on this on NPR this morning and I was surprised that that this was supposed to be so shocking. That extremely tiny dinosaurs sometimes became dinner for other types of creatures does not seem very surprising to me. Indeed, 24 hours ago I would quite willing to say that in the many millions of years of coexistence it would more shocking if no mammal ever ate a dinosaur. I really think that people are thinking too much about a full-grown T. rex or Apatosaurus. Now that would be surprising. People are also forgetting that the planet is a big place and that the 150 million years or so of the dinosaur "reign" is a very long time. That a few lineages of mammals could not have evolved to a moderate size in all that time would be more surprising to me.
Finally people must never forget what is unknown about the past far exceeds what is known. If that was not true we would not be hearing about some major new fossil find every few weeks.
--
Anti-spam: Replace "user" with "harlequin2"
I guess we're not hearing each other. Have there been, in the 150 years of the fossils-are-creatures-that-ived-a-long-time-ago era, other finds from the "Age of Dinosaurs" of this kind of larger predatory mammal? Or have there not been?
If not, or if they have been exceedingly rare, then that's something that requires explanation in and of itself--entirely apart from whatever mindset we may have been blinkering ourselves with.
My understanding of the previous paradigm is that there haven't been any/many finds of this kind. As a result, it has been proposed/assumed that the dinosaurs somehow managed to occupy the larger diurnal land-animal niches before the mammals did, and that once the dinosaurs found themselves in possession, the mammals were required to occupy a different set of smaller, nocturnal niches. (There may be an unnecessary suggestion of dominance-submission in the choice of verbs for this shorthand sketch, but you get to the same place if you talk in terms of the early mammals and the dinosaurs dividing up the niches--you still have to explain how one set of critters wound up pursuing one mode of life and how the other wound up pursuing the other.)
This was either a reasonable operating assumption in light of the fossil record, or it wasn't.
If Dr. Wilkins has warned of the dangers of our blinkered assumptions prior to these recent discoveries, or if he has predicted that larger, predatory mammal fossils were bound to be out there somewhere, then fine, he has a right not to feel surprised.
I think the rest of us can simply enjoy the vistas of thought opened up by these new finds, however, and that our "surprise" is more reasonably viewed as a result of a change in the data than of a shift in our pre-conceptions.