Summations Only

Quite right, and that's why this is how things actually are. It really is exceedingly difficult to draw lines between species and decide exactly where one stops and another begins. When enough of the intermediate steps are dead, we're left with two distinct populations and division is easy. Babriusas, for example, are sufficiently different from pigs and peccaries, without the existence of any suriviving, intermediate animals, that we're comfortable classifying them as seperate.But, then, how many species of babriusa are there. Traditionally, there was only supposed to be one. In 1980, however, a taxonomist took a look at this idea and decided it was a bit too simplistic. The babirusa should be split into four, distinct, sub-species. More recently, he's decided the different babirusas are more different than he previously gave them credit for, and reognised four different species. Other scientists disagree, and think they should be seen as more uniform.Of course, exactly where you lie on this debate changes depending on what, precisely, you define a species as. As a classic example, Mexico has somewhere between 101 and 249 recognised endemic bird species, depending on which exact definition of species you use.We can easily distinguish a whale and a hippo, but taxonomy is still filled to the brim with fuzzy boundaries and arguments over where x stops and y begins. It really is difficult to draw lines and classify things.Edited by caffeine, : broken tagsEdited by caffeine, : bizarre duplication of text

If Rodhocetus did live only in an enclosed sea, cut off from the Indian Ocean, then modern whales didn't descend from them. They would have died out at some point as their ocean shrunk (or perhaps before, for some unrelated reason).However, before the gap closed, blocking off the Tethys ocean from the wider seas, there would have been a traversable passage, with either Rodhocetus or similar relatives living on either side of it. The whales we can find fossils of would be those on the inside, since where they died is now above sea level and accessible to palaeontolgists. There were still other whales in the open ocean, however, continuing to adapt to life there.

Is this supposed to be referring only to mysticetes? There are still a lot of three, four, five, metre whales.

Yes, but that's evidently not true, which was why I asked if he was actually talking about mysticetes in particular.I have answered my own question in the affirmative by finding some of his work.

Rodhocetus is pictured without a tail fluke in message 1.Now, you are right that it can be a bit misleading when someone pictures a full skeleton as a fossil without indication of which bits are actually known from fossils. That's why you sometimes see skeletal reconstructions like this: with different shading used to differentiate between the bits known from fossils and the rest; which is the educated guess of the reconstructor.If you're complaining about artists reconstructions of fossils as living animals, then of course they have to include speculative elements. There's nothing dishonest about this - even the most complete fossil is not going to tell you how an animal looked in life. You have to fill in the gaps with speculation and conjecture; or it would not be possible to make any artist's impressions.Now, I do find it annoying that a lot of media presentation prefers the artist's impressions to pictures of the actual fossils; but that's not a problem with artwork - it's a problem of what the media thinks people would find more alluring.Incidentally, I'm not sure how relevant the terminal caudal vertebrae would be to whether Rodhocetus has a tail fluke. Whale vertebrae don't extend into the flukes. And Google images seems to suggest that the majority of artists reconstruct Rodhocetus without a fluke.