Torquarator bullocki

Posted 16 March 2005 by PZ Myers

The deuterostomes are a superphylum of animals that includes three phyla: the chordates (us!), the familiar echinoderms (sea urchins and starfish), and a peculiar group called the hemichordates (at times, you will see another phylum, the chaetognaths or arrow worms, grouped in the deuterostomes, but there is now evidence that they don't belong there). All are linked by their pattern of development. During gastrulation, animals form a structure called the blastopore, which is where migrating tissues tuck themselves inward to establish the three germ layers of the embryo. In deuterostomes, the blastopore will eventually become the anus. In the complementary category, the protostomes, which includes annelids and arthropods, the blastopore develops into the mouth.

The hemichordates are probably unfamiliar to most people reading this. They are marine worms that share two characteristics with us chordates: a hollow, dorsal nerve cord and a perforated feeding structure, the pharynx. They lack two others, the notochord and post-anal tail, hence the name hemichordate. There are two classes of hemichordate, the pterobranchs and the enteropneusts, which differ greatly in appearance and lifestyle.

Continue reading "Torquarator bullocki" (on Pharyngula)

12 Comments

DaveScot · 16 March 2005

h m! hp th rrw wrms gt clssfd crrctl sn. t's dffclt t mgn hw mn chldrn wll d f sm hds dss tht cld b crd f nl w knw whr t plc chtgnths n th tr f lf. Mb Grt Wht Wndr cn tll m hw mn chldrn's lvs r t stk vr ths. H wrks hs vstgl tlbn ff pplng knwldg lk ths vr d t sv chldrn.

Hrr, PZ, hrr.

PZ Myers · 16 March 2005

If you insist on being an idiot, I will have no regrets about deleting your comments and banning you. Knock it off now.

Michael Rathbun · 16 March 2005

...I will have no regrets about deleting your comments and banning you...

Speed the day.

Ken Shackleton · 16 March 2005

Oh my! I hope the arrow worms get classified correctly soon. It's difficult to imagine how many children will die of some hideous disease that could be cured if only we knew where to place chaetognaths in the tree of life.
— DaveScot

Typical response of the insecure ignoramus. He cannot comprehend any benefit and therefore must ridicule the work of others. What DaveScot and his kind [yes, they are a separate "kind"] fail to understand is that basic research often leads to knowledge and benefits that are completely unanticipated. Now, I doubt that the proper classification of these creatures will result in any medical breakthroughs....but who is to say what ideas such classifications may spark in the minds of others. Science should be supported, even when there is no obvious benefit other than simply expanding our knowledge base. DaveScot should crawl back under his rock.

PZ Myers · 16 March 2005

Please do not feed the troll.

I've got him covered, and will treat any further eructations from the buffoon appropriately.

DaveScot · 17 March 2005

Th fllwng rtcl hs nthng t d wth rrw wrms bt t's smthng shld b cgnznt f, Dr. Mrs.

http://www.thfr.rg/ndx.php/rtcl/5430.html

W t tk th hgh rd, b th w, cllng m bffn.

DaveScot · 17 March 2005

P.S.

Dn't sht th mssngr.

Matt · 17 March 2005

DaveScot

Is this what it's come to? You don't know enough about this particular topic to argue with it in any way, and there's no opening for you to insert your "mutation/selection" list, so you settle for ruining everyone else's enjoyment of the discussion? That's how you want to spend your time?

How sad. What an empty life you must lead.

Sorry to feed the troll, PZ. I'll stop now. But I think you might do him a favor by banning him - he may devote his energy to something worthwhile.

DvSct · 17 March 2005

Tstng, 1 2 3

H@y, th|s m|ght b f|_|n!

luminous beauty · 17 March 2005

perhaps DvSct belongs to a third super phyla where the blastospore produces a single orafice which is both mouth and anus. It deserves some study.

Engineer-Poet · 17 March 2005

Indeed (nb: the word is "orifice").

Perhaps Wavy Davy should also consider some remedial language and communications classes before he resumes his quest to re-write biology.

PZ Myers · 17 March 2005

Given that no one seems able to resist feeding the troll, and since the troll himself has nothing to contribute but blithering idiocy, I've decided to close the comments here.