Studied by 15 people
bilateria synapomorphies
cephalization
central nervous system
directional synapses
deuterostomes synapomorphies
coelom formed by enterocoely
pharyngeal gill slits
hemichordata synapomorphies
The body is divided into a proboscis, collar, and trunk
Stomochord (A dorsal extension of the pharynx)
Echinoderms Synapomorphies
Adults have pentaradial symmetry (5-way symmetry, each 72 degrees apart)
Well-developed water vascular systems
Endoskeleton of calcareous ossicles
Mutable connective tissue (Can alter rigidity)
Ecdysozoa Synapomorphy
Three-layered cuticle without locomotory cilia
Scalidophora Synapomorphies
Scalids (Spines that are attached to the introvert)
Nemotoida Synapomorphies
Chitinous cuticle greatly reduced (Replaced largely by collagen)
Only longitudinal muscles
Have introverts
Panarthropoda Synapomorphies
Segmentation (Usually associated with arthropods and vertebrates (kinds) and Seems to have evolved numerous times)
Paired appendages
Hemocoel (A blood filled cavity in the body, often with a heart and open circulatory system that aids circulation)
Complex brain
Tardigrada Synapomorphies
Connection form the first ventral ganglion to the protocerebrum
Onychophora Synapomorphies
Glue glands Trachea
Arthropoda Synapomorphies
Jointed exoskeleton
At least one pair of compound eyes
Cells lack flagella, except sperm
Cells lack cilia, except sensory cells
Myriapoda Synapomorphies
Tomosvary鈥檚 organ (sensory)
Tracheae for gas exchange
Malpighian tubes for excretion
Chelicerata Synapomorphies
Body divided into prosoma (acrons and 6 segments) and the opisthosoma (up to 12 segments and the telson)
No antennae
First pair of appendages are chelicera
Second pair of appendages are pedipalps (jaw-legs)
4 pairs of walking legs
Deutocerebrum is absent
Crustacea Synapomorphies
Strong support from DNA structure Eyes, cones of ommatidia have a tetrapartite crystalline structure
xenoturbella vs acoelomorpha
xenoturbella is bigger
How do Enteropnuesta feed?
food flows through probocsis, rejected particles move along collar, water exits through gill slits
How do Chaetognatha detect prey?
via vibrations
How do Chaetognatha reproduce?
spermatophyte attaches to partner, sperm migrates to oviduct, mouth develops secondly, germ granules are inherited by cells
What are the layers of cuticles in Ecdysozoa?
epicuticle, exocuticle, and endocuticle
What kind of symmetry do Echinoderms have as larvae?
bilateral
Attached vs Mobile Crinoidea
attached is very abundant whereas mobile is indo-pacific, both are more tropics oriented
What/how do asteroidea eat?
stomach inverts through mouth and wedges into bivalves where digestive glands absorb nutrients
Ophiuroidea vs Asteroidea
tube feet dont affect locomotion thin arms with heavy ossicles no anus or intestine no ambulacrol groove
How do Ophiuroidea move?
arms facilitate motion through a push and pull technique
What is the ecological impact of Echnoidea?
they create barren zones due to their high density and scraping of floor with teeth
What are some defense mechanisms of Holothoridea?
they can lose body parts sticky/toxic tubules
Kinorhyncha
Scalidophura size of grain (poorly known)
Primpolida
Rare scalidophura (Cambrian abundance)
Loriciferm
Scalidophura with high cell count found in anoxic sediment
Nematomorpha
long and skinny adults live in freshwater whereas juveniles are parasites in arthropods
What differentiates female and male Nematoda?
females have a stylet and buccal cavity whereas males have teeth
What does Arthropoda molting look like?
new exoskeleton is soft and hardens via tanning of proteins
What are the 5 pairs of head appendages used for in Crustacea?
1&2: sensory 3: mandibles 4&5: accessory feeding
What are some ways crustacea appendages are specialized?
swimming, grasping, clawing, respiratory
What are the type of Malacostraca?
Decapoda, Stomatopoda, Euphausiacea, Amphipoda, Isopoda
How are Isopoda compressed?
dorso-ventrally
How are Amphipoda compressed?
laterally
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