5. major phyla a. porifera: sponges b. cnidaria: corals, hydra, anemones, jellyfish protostomes:...
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5. Major Phyla
a. Porifera: Spongesb. Cnidaria: Corals, Hydra, Anemones, Jellyfish
Protostomes: Lophotrochozoansc. Platyhelminthes: Flatwormsd. Annelida: Segmented wormse. Mollusca: Chitons, snails, bivalves, cephalopods
Protostomes: Ecdysozoans
5. Major Phyla
Protostomes: Ecdysozoansf. Nematoda
- molt four times, resecreting their cuticle each time
- complete digestive tract
- some cephalization with anterior neural ganglion
- free living and parasitic
-human parasites: trichinosis, filariasis, elephantiasis, Ascariasis (two foot intestinal worms)
5. Major Phyla
Protostomes: Ecdysozoansf. Nematodag. Tardigrada
Cryptobiotic: can dehydrate to less than 1% of normal and endure for 10 years.
Can endure the vaccuum of space and 6000 atmospheres of pressure.
Thin exoskeleton, unjointed legs
5. Major Phyla
Protostomes: Ecdysozoansf. Nematodag. Tardigradah. Onychophora
Sister group to the Arthropods; thin exosleleton and unjointed legs, like tardigrades
Predatory; immobilize prey by shooting glue
5. Major Phyla
Protostomes: Ecdysozoansf. Nematodag. Tardigradah. Onychophora i. Arthropoda
Chelicerata
Arachnomorpha
Trilobita
Arachnids
Xiphosura
Mandibulata
Myriapoda
Hexapods
Remipedes
Vericrustacea
Crustacea
ExoskeletonJointed legs
From Regier et al. (2010)
5. Major Phyla
Protostomes: Ecdysozoansf. Nematodag. Tardigradah. Onychophora i. Arthropoda
Arachnomorpha clade:
Includes trilobites and Chelicerates. The chelicerates have two body regions, the cephalothorax and abdomen. They also have only one pair of appendages before the mouth – usually pincers. In spiders, these are fangs that inject poison.
5. Major Phyla
Protostomes: Ecdysozoansf. Nematodag. Tardigradah. Onychophora i. Arthropoda
The Mandibulata clade:Includes the myriapods (centipedes and millipedes) and crustaceans and their descendants (the hexapods). So, insects are the terrestrial descendants of crustaceans.
5. Major Phyla
Protostomes: Ecdysozoansf. Nematodag. Tardigradah. Onychophora i. Arthropoda
So in the mandibulata clade, we see duplication (myriapods), specialization (crustaceans), and reduction/fusion (insects)
5. Major Phyla
Protostomes:Deuterostomes:
j. Echinodermata
Internal skeleton composed of interlocking plates of calcium carbonate. A system of internal canals fills and empties tube feet.
5. Major Phyla
Protostomes:Deuterostomes:
j. Echinodermatak. Hemichordata
Hollow dorsal nerve cordPharygeal gill slits
All marine – some reach 8 ft in length
5. Major Phyla
Protostomes:Deuterostomes:
j. Echinodermatak. Hemichordatal. Chordata
4 characteristics: - hollow dorsal nerve chord - notochord - pharygeal gill slits - post-anal tail
5. Major Phyla
Protostomes:Deuterostomes:
j. Echinodermatak. Hemichordatal. Chordata
subphyla: Urochordata Cephalochordata Vertebrata
“Tunicates”: Mobile larvae, sessile filter-feeding adults - filter with the pharynx and gill slits.
5. Major Phyla
Protostomes:Deuterostomes:
j. Echinodermatak. Hemichordatal. Chordata
subphyla: Urochordata Cephalochordata Vertebrata
Mobile larvae, sessile filter-feeding adults - filter with the pharynx and gill slits.
5. Major Phyla
Protostomes:Deuterostomes:
j. Echinodermatak. Hemichordatal. Chordata
subphyla: Urochordata Cephalochordata Vertebrata
Pikaia – the earliest Chordate – dates from the Cambrian period
5. Major Phyla
Protostomes:Deuterostomes:
j. Echinodermatak. Hemichordatal. Chordata
subphyla: Urochordata Cephalochordata Vertebrata
“Jointed spine” – vertebrae. Although Hagfish lack this, so sometimes the group is called Craniata (has a skull)
Patterns in evolution:
Innovation, radiation, competitive contraction
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata
Hyperoartia: “Jawless fishes” Lampreys and Hagfish
Lamprey larvae look very much like cephalochordates
5. Major PhylaDeuterostomes: I. Chordata
Vertebrata
Hyperoartia: “Jawless fishes”
Evolve in late Cambrian, radiate in the Ordovician
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes – Jawed Vertebrates
Move from detritivores to predators
Lobe-finned Fishes
Ray-finned Fishes
Bony Fish
Acanthodians
Teleosts
Chondrichthyes (Sharks, rays)
PlacodermsArthrodires
Antiarchs
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes – Jawed Vertebrates
The Devonian was the “Age of Fishes” – a radiation of the first jawed vertebrates, dominated first by the Placoderms and then by Cartilaginous and bony fishes
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes – Jawed Vertebrates
The Devonian was the “Age of Fishes” – a radiation of the first jawed vertebrates, dominated first by the Placoderms and then by cartilaginous and bony fishes
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes – Jawed Vertebrates
Bony fishes dominate today: lighter skeleton and swim bladder
Ray-finned Fishes Lobe-finned Fishes
5. Major PhylaDeuterostomes: l. Chordata
Vertebrata Gnathostomes – Jawed Vertebrates
Bony Fishes (Osteichthyes) comprise 40% of living vertebrate species