Thursday, 21 February 2008

O Brontosaurus where art thou?

My Dad sent an email (and I have to credit him for my post title) sparked by some of the content from Joshua's narration on Dinosaurs:

Recently I have noticed the apparent disappearance of the Brontosaurus. When I was younger it was possibly the only dinosaur that I could name, and that would go for the rest of the population. Now you are telling me I had it wrong from the start.

So I did a little research. I read the "special edition for young people" of David Attenborough's "Discovering Life on Earth". At p109 it states "Apatosaurus [which used to be called Brontosaurus .....]". This suggests that it has been rebadged since my youth. Why?

For those of you out there who have been wondering the same thing, this was my answer:

I remember being taught something about this Brontosaurus issue in school. Joshua's dinosaur book answers this question very well (on p54) so I will quote it, with a few of my comments [in square brackets]:

Apatosaurus as called the "deceptive reptile". The name "deceptive" is well chosen due to the confusion its fossils caused. In 1877, Othniel Marsh gave the name Apatosaurus to a dinosaur whose hip and back bone fossils were found in a quarry near Morrison, Colorado. Over the next few years, more fossils of Apatosaurus were found, including fragments of a skull.

In 1879, Marsh gave the name Brontosaurus to an almost complete skeleton, found at Como Bluff, Wyoming, which was missing its skull. Marsh later reconstructed the skeleton of this "Brontosaurus", but gave it a square-shaped Camarasaurus-type skull that had been found in a different quarry, and in a different layer of strata. [This was a bit of bad science. A case demonstrating the proverb of the nature of assumptions.]

In 1975 [after Dad went to school and before I did] Dr Jack McIntosh and Dr David Berman convinced the scientific community that Apatosaurus and Brontosaurus were the same animal, and that Apatosaurus had a skull exactly like that of Diplodocus. [Perhaps the reason why Marsh was so hasty to name a second species in the first place had something to do with the cachet among the scientific community of having discovered and named two species of dino rather than just one - especially if this helped Marsh to successfully lobby for more funding for his dino discovery digs. I'm pretty sure this sort of premature public announcement happens fairly frequently in today also, especially in the areas of medicine and genetics. This paragraph does, however, raise another question for me, namely: How are Apatosaurus and Diplodocus different and will they too, at some stage, be recognised as being of the same species? (Perhaps males/females or skeletons of mature/immature individuals.) After all, the definition I was taught at Uni that is used to define species is "Individuals which are able to mate to produce viable, fertile offspring are members of the same species." Pretty hard to defend that argument on either side, I should think, when you only have the evidence of skeletons and fossilised ones at that. Consider the variety among the dog (Canis familiaris) species today! Yet some pretty unlikely mating combinations continue to prove that diversity of physiogonomy in this particular species is no barrier to the production of "viable, fertile offspring" aka mongrels.]

Since the rules used for giving scientific names to animals state that the first name given is the one kept, the name Apatosaurus stayed and Brontosaurus was dropped. [The problem with this resolution is that, in this case, the name Brontosaurus was and continues to be more well known, well, probably not among paleontologists, but for the rest of us commoners, at least. I'll probably be having a similar problem with discussions of the planet/non-planet Pluto in a few years with my kids or grandkids. This is a catch-22 with science studies: If you use old text books you read info that has since been disproved. But if you use very new textbooks, you'll probably be learning some info that will be disproved in a few years (or decades). And how to know which "fact" will be the one that is later "proved" to be "erroneous"?. This is one of the benefits I see in homeschooling, that I can point out to my kids that we don't know everything (!) and we probably never will (!!) so to test logic by looking for faulty assumptions and unfounded premises and ... generally try to make up their own minds if any given idea has merit or not.]

The confusion remains today as you can see by the "Brontosaurus" stamp issued by the US Postal Service in 1989. ...


Bec said...

I was very happy to discover that a mobile kit of the solar system I recently purchased, and the accompanying wall chart, did not include Pluto! Daniel (6), however, was not so impressed, as he continues to insist that the astronomical community has got it wrong and that Pluto is indeed a planet (since he has read all about the '9' planets in 'old' books he 'knows' he is right!). This will not be a problem if there is another pendulum shift in the future and Pluto becomes a planet again...
And people think 'science' is 'truth'!

Sharon said...

And he has all his sisters to convince with his interpretation of the "truth" about the planets as well! I wouldn't worry too much, by the time they're all through, they'll probably have discovered another "planet" and you'll be able to tell him he was just mistaken about the name...