Wednesday, April 22, 2009

The Despot

Today is a biggie for dino fans: at least three new species were announced and several dino-related papers published. Since we all know theropods are the best and everybody loves T. rex, I'll cut right to the quick:

First up is a brand new tyrannosauroid from China, Xiongguanlong baimoensis. Tyrannosaurs are of course known as "tyrant lizards," but Jaime Headden has coined another term for basal, small tyrannosauroids that fall outside the family Tyrannosauridae proper: despots. Xiongguanlong (pronounced SH'ONG-gwan-long) is a despot on the verge of becoming a tyrant, unlike its sort-of-namesake, the much earlier and more primitive Guanlong. As you can see in the skeletal drawing here (from the Field Museum press kit), it also has a very narrow, almost spinosaurian skull (the authors describe it as "longirostrine", or long-snouted). This helps muddy up the presumed straight-line (ha!) evolution of tyrannosaur skulls from lightweight, boxy primitive forms to heavyweight, bone-crushing advanced forms (though at least one proper tyrant, Alioramus, also has a fairly narrow snout).

One fun thing to do when new dinosaurs get lots of media attention to the point people are sending out press kits (what, was Paul Sereno involved in this?) is to laugh at the silly "science" journalists employed by most newspapers and see just how much they misunderstood what the scientists told them. In all fairness, most media hype about new dinosaurs is just that, and the scientists are sometimes complicit in this. After all, what's exciting about a new find for scientists because it clears up some small details of evolution might be lost on the general public unless they see it as filling in some MAJOR gap (people love "missing links" even though there's no such thing, every species is a link to some other species).

Here's an example from the BBC News story on Xiongguanlong:
  • "Tyrannosaurus rex may have had much smaller ancestors"

No kidding? You mean it didn't evolve from even larger tyrannosaurs? Not to mention all the media hype two years ago over Guanlong, which was... a small ancestor of T. rex. Or Appalachiosaurus before that. Or Dilong before that. Eotyrannus before that. The caption aside, the text mainly puts this in the right context--it's not a new discovery that tyrannosaurs had small ancestors. What's significant is that it fills in a gap between the Late Jurassic and Early Cretaceous despots and the Late Cretaceous tyrants, hailing as it does from the middle of the Cretaceous Period. That's why, I guess, the story on ScienceNews dubbed it the "Goldilocks Tyrannosaur."

Anyway, I'm still working on getting this paper and reading more than just the abstract and Makovicky's comments in news articles, so I'll keep an eye on the threads to see if any more fun info on despots comes up.

1 comment:

  1. We seriously need science reporting fail blog.
    that bbc quote just made my day. :D