How many species of dinosaur have paleontologists discovered?

September 12, 2013 9:15 AM

That's it...that's the whole question. What is the sum total of individual dinosaur species that have been identified? (Asking for my 6 year-old, and myself of course)!
posted by pandabearjohnson to Science & Nature (5 answers total)

This USGS page has some info, though it's a decade out of date now. There are some updated numbers and methodology in this NYTimes article from 2006-- you might contact the authors of the paper to see if they have re-run any of the data.
posted by jetlagaddict at 9:23 AM on September 12, 2013

And here's a 2010 interview that still suggests around 700-800 species of dinosaurs identifies, but which also suggests a discovery rate of 30 or so a year, if you wanted to extrapolate out to today.
posted by jetlagaddict at 9:32 AM on September 12, 2013

Best answer: From wikipedia: Using fossil evidence, paleontologists have identified over 500 distinct genera and more than 1,000 different species of non-avian dinosaurs.

The complication is that you can't really pin down a number of species; with dinosaurs it's better to go by genus. For instance, you think Stegosaurus, you probably think of a specific kind (species) of dinosaur. But Stegosaurus is actually a genus, and there are at least like 5 species of stegosaurus.

Every new dinosaur found is potentially a new species. Let's say you find a femur that's about 5 feet long and of a particular thickness. It's similar, but not exactly the same, as a known diplodocus species, say d. longus. It could either be a whole new diplodocus species OR a d. longus that's just a different size (just like there are size variants in all people but we're all homo sapiens). It's unlikely you'll find the entire skeleton intact, so you just may never know. There's just not a complete enough fossil record to make the call sometimes. Even if you do make a call on it being another species, a future fossil found could contest that earlier determination and just broaden the definition of what we know d. longus to be. So classifying it into a genus (with a question mark) is generally how it goes.

Long story short, giving an estimate on number of species is tricky, and probably not what you and your kid are looking to know anyway.
posted by phunniemee at 9:33 AM on September 12, 2013 [2 favorites]

It can be hard to say. We might have two triceratops skulls. One has big horns. One has small horns. Are they two different species, or is one male and the other female? Is one adult and the other a juvenile? New ways to study the bones are always being developed, so the answers to these questions are always being updated.
posted by Lou Stuells at 11:16 AM on September 12, 2013

What an awesome question. I don't have any input, not being a paleontologist myself, but I do remember well asking my mother to read out loud the NASDAQ number displayed on the news every night because I thought it was the BIGGEST NUMBER EVER and therefore the coolest thing ever. So I wonder if you can come to some rough approximation, based on the data cited above, but then tell little pandabearjohnson that there could be many more (in part based on what Lou Stuells said), and blow his/her tiny mind with the enormity of the number + the possibility of an even bigger number?
posted by AthenaPolias at 2:14 PM on September 12, 2013