2. unifying synapomorphies of mammals???

4. monophyly. paraphyly, polyphyly…

6. deuterostome and chordate phylogeny is in a mess…

7. Chordate Phylogeny
“Protostomes” vs. Deuterostomes

9. Chordate Phylogeny
Echinodermata
Ancestral
deuterostome

10. Echinodermata about 6000 species ha’uke’uke’ula’ula
secondary radial symmetry (oral/aboral)
bilateral larva (trochophore)
endoskeleton of CaCO3 (articulated pieces)
eucoelomate
benthic marine creeping predators or herbivores

11. Chordate Phylogeny A P
Trochophore larva

12. Chordate Phylogeny “eucoelomate” body wall gut wall coelom lumen
outside
coelom
“eucoelomate”

13. Chordate Phylogeny Ancestral deuterostome Echinodermata Hemichordata
Echinodermata + Hemichordata = monophyletic clade - Ambulacraria
Ancestral
deuterostome

14. Hemichordata Enteropneusts AKA Acorn worms trunk collar proboscis
bilateral symmetry in adults; tripartite body plan (proboscis, collar, trunk)
bilateral larva (trochophore)
no endoskeleton
eucoelomate
pharyngeal perforations
benthic marine burrowing sediment (enteropneusts) or suspension (pterobranchs) feeders
proboscis
Enteropneusts
AKA Acorn worms

15. +
bilateral symmetry in adults; tripartite body plan (proboscis, collar, trunk)
bilateral larva (trochophore)
no endoskeleton
eucoelomate
pharyngeal perforations
benthic marine burrowing sediment (enteropneusts) or suspension (pterobranchs) feeders
Pterobranchs

16. Chordate Phylogeny Body wall H2O Pharynx lumen
pharyngeal perforations…

17. Chordate Phylogeny Ancestral deuterostome A Echinodermata Hemichordata
Echinodermata + Hemichordata = monophyletic clade - Ambulacraria
Ancestral
deuterostome

18. Chordate Phylogeny Ancestral deuterostome Xenoturbellida Echinodermata
Hemichordata
Echinodermata + Hemichordata + Xenoturbellida = monophyletic clade - Xenoambulacraria
Ancestral
deuterostome

19. Chordate Phylogeny Xenoturbella bocki no brain no gut no gonads
thought to be a flatworm
thought to be a mollusc
now thought to be a deuterostome - based on ribosomal RNA sequeces

20. Chordate Phylogeny Ancestral deuterostome X Xenoturbellida
Echinodermata
Hemichordata
Echinodermata + Hemichordata + Xenoturbellida = monophyletic clade - Xenoambulacraria
Ancestral
deuterostome

21. Chordate Phylogeny The traditional point of view… Ancestral
Xenoturbellida
Echinodermata
Hemichordata
The traditional point of view…
Ancestral
deuterostome

22. Chordate Phylogeny The traditional point of view… Ancestral
Phylum Chordata:
notochord
dorsal, tubular nerve cord
pharyngeal perforations
skeletal/muscular post-anal tail
Xenoturbellida
Echinodermata
Hemichordata
Echinodermata + Hemichordata + Xenoturbellida = monophyletic clade - ambulacraria
The traditional point of view…
Ancestral
deuterostome

23. Chordate Phylogeny notochord chordamesoderm…
an axial (longitudinal) rod of discoidal modified muscle cells surrounded by a sheath of fibrous protein
a turgid, stiffening skeletal element that opposes muscle contraction
Sherman High School…
notochord - formed by “chordamesoderm” that migrates through the blastopore during gastrulation
chordamesoderm “induces” the formation of…

24. DBL

25. neurectoderm
chordamesoderm

26. dorsal tubular nerve cord
chordamesoderm
Lumen

27. dorsal tubular nerve cord
neural plate
chordamesoderm
Lumen

28. neural folds
Lumen

29. neural groove
Lumen

30. dorsal tubular
nerve cord
Lumen

31. Chordate Phylogeny
pharyngeal perforations
Pharynx lumen
Body wall
H2O

32. Chordate Phylogeny
muscular and skeletal post-anal tail

33. Chordate Phylogeny Urochordata Ancestral deuterostome Xenoturbellida
Phylum Chordata…
notochord
dorsal, tubular nerve cord
pharyngeal perforations
skeletal/muscular post-anal tail
Xenoturbellida
Echinodermata
Urochordata
Hemichordata
Ancestral
deuterostome

34. Urochordata Sea squirts AKA tunicates “larvaceans” about 1500 species
“Die Locher sind die Hauptsache
an einer Sieb”

35. pharyngeal perforations
asymmetric as adults
bilateral larva (tadpole)
possess all chordate characters as larvae
“urochordata” because the notochord is in the tail
endostyle
sessile or pelagic marine filter feeders

36. Tunicate larva oral siphon statocyte pharynx atrial siphon notochord
adhesive papillae

37. Tunicate larvae…
acoelomate?
tubular nerve cord?

38. Chordate Phylogeny Urochordata Cephalochordata Ancestral deuterostome
Phylum Chordata…
Xenoturbellida
Echinodermata
Urochordata
Cephalochordata
Hemichordata
cephalochordata:
vesicular brain
metamerism
chordate characters in adult stage
Ancestral
deuterostome

39. “lancelets”, “Amphioxus”, Branchiostoma, about 15 species
muscle bundles
notochord
dtnc
tail
fusiform body shape
vesicular brain
notochord is the axial skeletal element
notochord goes all the way to the anterior end of the body (“cephalochordata”)
pharynx is large with many perforations
metameric musculature
benthic marine burrowing filter feeders
sister group of the craniates
pharyngeal basket
note metamerism in musculature

41. dtnc
notochord
muscle bundle
pharyngeal bar
intestine
gonad
atrium
pharynx lumen
endostyle

42. Chordate Phylogeny Craniata Urochordata Cephalochordata Ancestral
Phylum Chordata…
Xenoturbellida
Echinodermata
Craniata
Urochordata
Cephalochordata
Hemichordata
c+c: metameric mm; vesicular brain
Craniata:
tripartitie brain
cranial capsles
Ancestral
deuterostome

43. Chordate Phylogeny Craniata Urochordata Cephalochordata Ancestral
Phylum Chordata???
Xenoturbellida
Echinodermata
Craniata
Urochordata
Cephalochordata
Hemichordata
chordata…
Ancestral
deuterostome

44. Chordate Phylogeny Craniata Urochordata Cephalochordata C + C
Phylum Chordata???
Xenoturbellida
Echinodermata
Craniata
Urochordata
Cephalochordata
Hemichordata
C + C
c+c…
Ancestral
deuterostome

45. Chordate Phylogeny P A
notochord
mouth

46. Chordate Phylogeny P A otic optic olfactory dtnc notochord
the craniate brain is vesicular and “tripartite”: the olfactory and optic lobes,
and the otic placodes…
which are brain centers associated with the senses of smell, vision, and “hearing” (including proprioception)
these brain centers are in turn associated with the parts of the “primitive” vertebrate brain: the prosencephalon, (mesencephalon), and rhombencephalon

47. Chordate Phylogeny P A otic capsule optic capsule nasal capsule
notochord A
Associated with the olfactory and optic lobes and the otic placodes are cartilaginous “capsules” that surround and protect the brain sections and associated sense organs

48. Chordate Phylogeny P A otic capsule optic capsule nasal capsule dtnc
notochord A
The nasal capsule is a “cranial cartilage” associated with the olfactory lobe…

49. Unifying synapomorphies??
Chordate Phylogeny
otic capsule
optic capsule
nasal capsule P
dtnc
notochord A
Unifying synapomorphies??

50. Chordate Phylogeny Craniata Urochordata Cephalochordata C + C
Xenoturbellida
Echinodermata
Craniata
Urochordata
Cephalochordata
Hemichordata
C + C
Craniata:
tripartitie brain
cranial capsles
Ancestral
deuterostome

51. 29
1.5 M…