Darren and the Dinosaurs
(sorry, Darren, I couldn’t resist that. Danny and the
Dinosaur was the first book I remember reading.)
I’ve talked about Dr. Darren Naish before. A paleozoologist and science writer with a specialty
in dinosaurs but interests everywhere, Darren’s blog Tetrapod Zoology is
reliable and fascinating reading on everything from sea serpents to orangutans
to every kind of zoological oddity.
The blog caught my attention this week for its headline about
sauropod dinosaurs and whether scientists are creating too many species. He notes some 50 “non-bird dinosaurs” are
described every year, and there’s a proliferation of North American longnecks
that some paleontologists think is overdone – there are 30+ species from just the Morrison
Formation (Upper Jurassic Period). One need
not understand the subtleties of classifying dinosaurs (I certainly don’t) to
wonder how complete the fossil record is and whether we know a few or most of
the dinos from a particular place and time.
His response is that there are gaps where we know almost none of the dinosaurs. Some caution is called for when we have only fragmentary
remains, but given the time scale we’re dealing with (remember T. rex is closer
in time to us than to most other dinosaurs we common folk have heard of) and the global spread of dinosaurs, there's a lot of room for discovery Indeed, we sometimes, in effect, don’t have enough
dinosaurs: an eternal war rages between those who think Nanotyrannus is a
young T. rex and those who think it’s a species. (The latest research is on the
T. rex side, leading me to brilliantly pun “sic semper nanotyrannus.”)
One estimate (not from this source) is that the average
lifetime of a species is 3 million years.
In the 140 million years of the Mesozoic, there’s room for a LOT of
dinosaurs. The known species include
cool mysteries like Amphicoelias fragillimus, now Maraapunisaurus,
described in 1878 from a single, now-lost vertebra so large it indicates a dinosaur
even bigger than the recently found South American giants. It might, given its resemblance to the famous
Diplodocus, be “a diplodocid diplodocoid, and probably a diplodocine
diplodocid diplodocoid.” Umm, ok.
OK, that’s all the dino-rambling for today. Buy Darren’sbook.
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