Lophotrochozoans
• Linked by trochphore larvae (e.g. mollusc and annelid) and lophophore
• DNA sequence support as well
Tree of life, Moore text andlarge scale sequencing of DNA : Little resolution
rDNA Tree
Passamaneck & Halanych
Molecular Phylogenetics and Evolution
40 (2006) 20–28
Crinoid and sea star
Hemichordate
Echinodermata
• Literally – ‘Spiny skinned’
• A completely different body plan from
other taxa (embryo and larval characters
link echinoderms to chordates:
deuterostomes)*
• Radial symmetry 2o within the Bilateria
• Oral and aboral surfaces
• Habitat: all marine. About 6,500 species
1
Asteroidea
ABORAL
Sieve plate
ORAL
http://www.sbg.ac.at/ipk/avstudio/pierofun/planci/images/vascular.jpg
http://www.duiops.net/seresvivos/galeria/estrellas
/Sea%20Star,%20Palau,%20Micronesia.jpg http://home.comcast.net/~rhosgobel/images/sea-star-feeding-600-ra
http://tidepool.st.usm.edu/pix/ophiuroid.gif
http://people.hws.edu/mitchell/cards01/LEI-039.jpg
http://www.humboldt.edu/~natmus/newsletter/Tidepools/28-Brittle-Stars.jpg
2
ABORAL
Opiuroidea
(Brittle stars)
(gill)
ORAL (location of madreporite)
http://www.palaeos.com/Invertebrates/Echinoderms/Ophiuroidea/OphiuroidInternal.gif
http://animaldiversity.ummz.umich.edu/site/resources/
Grzimek_inverts/Ophiuroidea/v01_id145_con_ophanat.jpg/medium.jpg
Echinoidea
http://www.calstatela.edu/faculty
/eviau/edit557/oceans/norma/osurchn.gif
http://www.seashells.org/images/pencilurc.jpg
http://news.bbc.co.uk/1/low/sci/tech/1461923.stm
3
MADREPORITE (SIEVE PLATE)
GONAD
STONE CANAL
GUT
ONE JAW OF
ARISTOTLE’S
LANTERN
Crinoidea
ORAL
TUBE FOOT
ORAL
• Sessile
• Very diverse fossil
record
ABORAL
4
Secondary bilateral symmetry:
HOLOTHUROIDEA
Sea cucumbers
http://animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts
/Holothuroidea/v01_id245_con_holanat.jpg/medium.jpg
http://www.ucmp.berkeley.edu/echinodermata/seacuke.gif
Reduced tube feet in two rows
(dorsal ambulacra)
Well developed tube feet on three ventral amulacra
(forming “sole”)
http://www.com.univ-mrs.fr/IRD/atollpol/ecorecat/images/holoturie.jpg
http://people.bu.edu/ibeandy/Pics/SeaCucumber1.jpg
5