top Whale & Dolphin taxonomy from FT Exploring        


Are dolphins considered whales?
Dolphins, whales and cetaceans.

Are dolphins whales? We explore the great dolphin, whale, cetacean controversy that I just made up; also we introduce you to the exciting field of taxonomy, and why whales and dolphins desperately need taxonomists; examples are given of whale and dolphin taxonomy and nomenclature; and finally, a totally unrelated brief essay on the facial expressions of dolphins (or the lack thereof).
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 Are these happy seeming little (relatively speaking) guys really in the same club as the big ol' whales?
Are they smiling?

Dear Dr. Galapagos,
Are dolphins considered whales?

from Parma, Ohio

     These dolphins belong to the suborder Odontoceti, which means they are "toothed whales". Other toothed whales include sperm whales (the biggest), beaked whales, bottlenose whales, porpoises, beluga whales, narwhals, river dolphins, pygmy sperm whales, and dwarf sperm whales.

     Killer whales are in the same family as dolphins. The big name that taxonomists use for this family is Delphinidae. Members of the delphinidae family are ocean going dolphins (as opposed to river dolphins). So killer whales are in the same family as dolphins. Does that mean they are not whales? Should we call them Killer Dolphins? Does it matter?
Is it nomenclature or taxonomy?
      Nomenclature is all about what things should be called. Taxonomy is all about deciding how to organize and group living things logically and who is related to whom. But when it comes to choosing a name that all scientists will clearly understand it is usually best to start with taxonomy. The great gods of Taxonomy decide who is an official cetacean and who isn't. Nobody is officially regulating inexact words like whale and dolphin. This means we laypersons are free to be as confused as we like, and to argue all we want, about them. Gives us something to do.
     The strange looking Narwhals (pictured above) are also members of the toothed whale (odontoceti) club. But they are not in the dolphin family. They are in the Monodontidae family. The other lonely member of this family is the Beluga whale. Monodontidae are white whales with blunt heads and no dorsal fin. That big spike coming out the whale's forehead is really its left upper tooth. Only males have this "tusk" and no one is quite sure what it is used for. Narwhals live in the arctic and are said to be rare.

      I poke a little fun at taxonimists here, but it is really a fascinating and fast changing field. It's changing because we are learning more, each day it seems, about the genetic code of more and more species and discovering there are some surprising possible new relationships (see note on sperm whales in table below) amongst the various species.
      And, of course, we laymen need them to settle questions of nomenclature. Because words like Dolphin and Whale are often not clearly and officially defined, we need the taxonomists to give us words like cetacean and delphinidae, that are clearly defined.
      They are all in the order cetacea. The name cetacea comes from the greek word cetus, which some people like to say means whale (though it is doubtful that the ancient Greeks understood very much about whales at all - it wasn't their fault, of course, but for the most part they didn't know a whale from a really big fish from a sea monster).
The killer whale above is chasing a seal. Seals are not cetaceans. They are pinnipeds. Seals, sea lions, and walruses are pinnipeds.
     This handsome fellow is a pinniped, not a cetacean. Almost anybody can tell the difference. Pinnipeds and cetaceans are both considered marine mammals. I wouldn't tell him to his face, but I gotta think some of the other pinnipeds are a little cuter.

     Sea lions are cute. Sea lions are more flexible than seals, and get around on land a lot better (which isn't saying much). Killer whales will enthusiastically eat either seals or sea lions (and many other marine critters too). They are non-biased eaters.
     Inside the mouth of the orca (a kinder gentler name for killer whale), the last thing that some seals, sea lions, fish, squid, porpoise, whales, and many other sea creatures ever see. Orcas are friendly to each other, and pretty friendly to us humans, but they will eat just about everybody else.
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Dear Steve,
     I wrote you and told you that dolphins are indeed (never trust people who use the word indeed) whales, and that is still my opinion.  But not everyone agrees with me (and I am not a whale biologist), so it requires a little more explanation than I gave you in my e-mail response.

     If you look around the web or look in a lot of other sources for information on whales (like books - books are still the best place for information - go there often) you will find, as I did, that some people say dolphins are whales and some people seem to say dolphins are not whales. It is common for even scientists to separate these marine mammals into whales, porpoises, and dolphins (in fact this seems to be the norm). And sometimes the same people who say, or at least imply, that dolphins and porpoises are not whales will turn right around and tell you that dolphins are members of the "toothed whale" club (club is not an official science word), or more correctly, the suborder "Odontoceti".  And so the confusion starts.  Apparently they are "toothed whales" but not whales!?

Well darn it anyway! What's going on?

Will the Correct Taxonomist Please Stand Up?
     Somewhere in the many hallowed halls of big time education places there are scientists called taxonomists (no they didn't invent taxes) who have taken it upon themselves to classify all living things into kingdoms, phylums, classes, orders (and sometimes suborders), families, genuses, and last but not quite last, species (there are also subspecies sometimes). These are lonely nit-picky people who argue amongst themselves and lose sleep at night worrying whether or not dolphins are whales. Well, actually, what they really worry about is the confusion that is caused by every day non-whale biologist ordinary Joe's like you and I using such unclear words as dolphin and whale.

     We have met the problem and it is us. We laypersons tend to not be too careful with our words. When most of us say whales we mean something kind of vague but generally a lot bigger than a dolphin. And when we say dolphin, we mean the little "smiling" guys that put on shows for us at places like Marine World. But what about killer whales. They are supposedly in the same suborder as dolphins (and even in the same family - Delphinidae) but they have whale in their name. The same is true of pilot whales and narwhals (note that whal is not whale) and beaked whales and bottlenose whales.

     Well, let's be frank about this (you be Frank and I'll be Earnest). It doesn't really matter that much to most laypersons (except us know-it-alls who like to show how much we know by correcting people who don't know as much as we do), but it matters to whale biologists. It is important when they talk or write to each other that they be very clear so that there are no misunderstandings. Or at least as few misunderstandings as possible. So what do whale taxonomists do? They decide which whales are related to which other whales and organize them all into families and orders and genuses and species. Then they make up very precise names (with the help of an old language like Latin) and define as precisely as possible what that name applies to. Then everybody knows just what they are talking about. Even people who speak different languages know. Whether they speak Russian or Spanish or Swahili, they all know that a Balaenoptera Musculs is a blue whale and a Tursiops Truncatus is a bottlenose dolphin.

Will the Real Cetacean Please Swim Forward
     Since general words like whale and dolphins can be a unclear they use another word. The word they use is cetacean. They are all cetaceans. All whales, dolphins, and porpoises are cetaceans. No one is allowed to argue about this (in theory - in reality there is always discussion and things are always changing).
     So chill out! The next time someone starts to argue about whether or not a dolphin is a whale just roll your eyes, smile smugly, and say, "I don't get bogged down in such silly arguments. To a marine biologist they are all cetaceans".

     (And, of course, you can also tell them that Dr. Galapagos says a dolphin is a whale is a cetacean. That should settle it.)

And What About Chelonians?
     I might also add that word confusion like this is an issue in all fields of science. Another good biology example of this are the words turtle and tortoise. Most people would say a tortoise is a turtle but a turtle is not necessarily a tortoise. But some people say a turtle is never a tortoise because turtles live in water and tortoises live only on dry land. Starting to get confused again? Just when you thought you were starting to understand? Well don't worry about it. Be happy! Taxonomists have again come to the rescue.
     Turtle and/or tortoise experts have their own word too! Their word is chelonian. The five dollar word for reptiles with shells that most of us call turtles or tortoises is chelonian.
They are all chelonians
And this web site should have been called the Flying Chelonian. And I, Dr. Galapagos, am a know-it-all Chelonian (who hates water).

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Teeth or Baleen?
      Here is how the taxonomist guys tell us to classify whales, er, I mean cetaceans.
     First there is the Kingdom. They are in the animal kingdom, or Animalia, to be all "Latiny" about it.
     Next there is a Phylum. Cetaceans are in the Chordata phylum, which means they are vertebrates (they've got backbone).
     Of course, they've got Class, lots of class. They are in the Mammalia class. That's us too! We humans are mammals too. Just like the whales. How cool is that?
      Next comes Order. Their order is Cetacea. Proud members of the Order of the Cetacea.
     Sometimes there are Suborders (no, it's not what you get at Subway). There are two suborders, toothed whales and baleen whales, in the Cetacean order. We'll define them in another article. The scientist name for toothed whales is Odontoceti. The scientist name for baleen whales is Mysticeti. (Because they are so mysterious?) Baleen whales include blue whales (really really big), fin whales, right whales (there are no wrong whales), gray whales, humpbacks and others.
     After suborder comes Family. Killer whales and dolphins are in the Dolphinidae family. By our count there are 11 cetacean families.
     After Family comes Genus. Check out the table below to see some examples of genus and species names.
     Finally, we get to the specific Species. A good source tells us there are 79 known species of cetaceans.
     The further down the list you go the more alike the animals get. Animals of the same species are so much alike they can reproduce and their offspring can reproduce more of the same.
     Click on this to see a table of some examples of how whales are classified.
     The friendly looking (but not really smiling) cetacean above is a Beluga whale. The drawing below represents a beluga family.

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Answer to Question "Are they really smiling?"
     They sure look like they're smiling!  And it really looks like they're laughing when their mouths are open. But scientists get bugged when we humans imagine that animals are just like us. So a scientist would point out that dolphins can't make any facial expressions at all. Their mouth and eyes are always fixed in what looks to humans like a permanent smirk or grin (they would make great poker players - if they could hold the cards). So I have to officially say they are not smiling like we think of smiling. Nevertheless, they are fun to look at, and how do we know they aren't laughing on the inside?
Below is a table showing how whale biologists (oops, I mean, Cetacean biologists) have classified some of the better known cetaceans. Note the comments below the table concerning sperm whales.
  Bottle Nose Dolphin Killer Whale Sperm Whale** Blue Whale Humans
Kingdom Animalia Animalia Animalia Animalia Animalia
Phylum Chordata Chordata Chordata Chordata Chordata
Class Mammalia Mammalia Mammalia Mammalia Mammalia
Order Cetacea Cetacea Cetacea Cetacea Primates
Suborder Odontoceti Odontoceti Odontoceti** Mysticeti  
Family Delphinidae Delphinidae Physeteridae Balaenopteridae Hominidae
Genus Tursiops Orcinus Physeter Balaenoptera Homo
Species truncatus orca macrocephalus musculus sapiens
  Tursiops truncatus Orcinus orca Physeter macrocephalus Balaenoptera musculus Homo sapiens
**Some whale biologists say sperm whales are more closely related to baleen whales than the other toothed whales (Odontoceti). This is because of DNA similarities, certain physical similarities, and similar development of the embryo stage.
I'm just kidding about Taxonomists. Some of my best friends are taxonomists. Though I try not to be seen in public with them.
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