Clade for ARTHROPODA & ONYCHOPHORA
SEGMENTED PROTOSTOMIA (after Ruppert & Barnes'94 p. 1052, Brusca & Brusca'90 p. 683)
==O*=== ONYCHOPHORA (velvet worms)
=P*=|
<<=OTHER PROTOSTOMIA==| ==A*================================== TO ARTHROPODA ===>
|
=========== ANNELIDA (segmented worms)
P- a) elongate body of many similar segments**, b) ventro-lateral appendages, c) growth by molting,
d) ectodermal cilia lost,
CHELICERATA: a) two tagmata (cephalothorax without distinct head & abdomen), b) mouth lies before first segment embryologically, c) seg. #1 limbs= chelicerae (no antennae; may be pincer-like or fangs)
CRUSTACEA: a) 1st antennae uniramous**, b) 2nd antennae biramous, c) mandible is simple (gnathobasic), d) sessile (non-stalked), compound eyes**, e) many similar, biramous, phyllopodous thoracic limbs, f) telson with rami, g) nauplius larvae
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Copyright © 1997 by A. Richard Palmer. All rights reserved. (revised March 26, 1997)
O- a) external segmentation suppressed, b) unique oral papillae, c) lobopod limbs, d) tracheal system
A- a) lateral compound eyes, b) calcification of cuticle, c) fully segmental sclerites (body-wall cuticular plates), d) jointed appendages with intrinsic muscles, e) complete loss of motile cilia/flagella (except some sperm)
ARTHROPODA (tree/traits: Brusca & Brusca'90 p. 485, 538, 589, 598, 659, 683, 691; taxa in FULL UPPER CASE indicate the four arthropod subphyla)
==A*===== Arachnida (spiders, mites, scorpions, etc.)
=C*==|
=========CHELICERATA===========| ==X*===== Merostomata (horseshoe crabs)
| |
| =P*=========== Pycnogonida (sea spiders)
|
<<=| =====TRILOBITOMORPHA===================== (extinct trilobites)
| |
| | === Thysanura (silverfish and firebrats)
| | ===Insecta==|
| | | === Pterygota (winged insects)
=T*=| =Hexapoda==|
| | =============== Collembola (springtails)
| =UNIRAMIA==|
| | | =========== Chilopoda (centipedes)
| | ==Myriapoda====|
=M*=| =========== Diplopoda (millipedes)
|
=CRUSTACEA==============================================================>
*Traits supporting each clade (** plesiomorphic- a primitive state, not unique to clade):
C: a) cephalothorax carapace shield, b) 1st or 2nd abdominal segment modified as genital somite
P: a) pre-oral proboscis, b) ovigers, c) abdomen reduced or absent, d) 9-segmented walking legs, e) multiple pairs of gonopores on some or all legs
A: a) abdominal limbs reduced, lost or modified as spinnerets, b) loss of compound eyes
X: a) enlarged cephalothorax with large shield, b) abdominal limbs modified as book gills, c) long, spiked telson
T: a) 3 tagmata, b) mouth lies before second segment embryologically, c) seg. #1 limbs= antennae, d) 4 pr. post-oral head segments with limbs similar to thorax
TRILOBITOMORPHA: a) 3 tagmata (cephalon, thorax, pygidium), b) body dorso-ventrally flattened, c) limbs of post-oral head segments similar to limbs of thorax**
M (Mandibulata): a) 2 tagmata (head, trunk of many similar segments), b) 5 pr. head appendages (2 pr. antennae, 1 pr. mandibles, 2 pr. maxillae)
UNIRAMIA: a) 2nd antennae lost, b) mandible is 'whole-limb', c) unique tracheal system, d) uniramous limbs
Hexapoda: a) 2nd maxillae fuse as labium, b) 3-segment thorax with limbs, c) 11-segment abdomen without limbs
Myriapoda: a) loss of compound eyes, b) loss of palps on 1st and 2nd maxillae, c) repugnatorial glands
CRUSTACEA: a) 1st antennae uniramous**, b) 2nd antennae biramous, c) mandible is simple (gnathobasic), d) sessile (non-stalked), compound eyes**, e) many similar, biramous, phyllopodous thoracic limbs, f) telson with rami, g) nauplius larvae
CRUSTACEA (tree/traits as for Arthropoda)
======1*========================= Remipedia
<<==CRUSTACEA==|
| ===3*====================== Cephalocarida
===2*=|
| ==5*=================== Branchiopoda (fairy shrimp, water fleas, etc.)
=4*=|
| ==7*=============== Maxillopoda (copepod, ostracod, barnacle, etc.)
=6*=|
| ==8*========= Leptostraca
==Mal=|
| ==10*==== Hoplocarida (mantis shrimps)
Mal= Malacostraca =9*=|
| =12* Peracarida (mysids, amphipods, isopods, etc.)
=11*=|
=13* Eucarida (krill, shrimps, lobsters, crabs, etc.)
*Traits supporting each clade (** plesiomorphic- a primitive state, not unique to clade):
1: a) 1st antennae biramous, a) raptorial mouth appendages, b) seg. #6= maxilliped, c) many similar trunk segments (no trunk tagmata) with paddle-like biramous legs, d) pre-antennal process, e) eyes lost
2: a) 3 tagmata (head, thorax, abdomen), b) reduced number of body segments
3: a) abdominal appendages lost, b) abdomen of 11 segments, c) seg. #5= leg-like, d) compound eyes lost
4: a) fully developed carapace, b) abdomen has fewer than 9 segments
5: a) maxillae (segs. #4 & #5) reduced or absent (trunk segment number & limbs vary greatly)
6: a) thorax has fewer than 11 segments, b) abdomen has fewer than 8 segments
7: a) thorax has fewer than 7 segments , b) abdomen has fewer than 5 segments, c) unique naupliar eyes
Mal: a) thorax of 8 segments with similar limbs, b) abdomen of 7 segments + telson, c) carapace covers head & thorax, d) 1st antennae biramous, e) stalked eyes, f) gills on thoracic limbs
8: a) 2nd antennae uniramous, b) abdomen of 7 segments + telson **, c) similar, phyllopodous thoracic limbs**
9: a) abdomen of 6 segments + telson, b) thoracic limbs stenopodous, c) telson lacks rami
10: a) carapace covers head & 4 thoracic segments, b) limbs of first 5 thoracic segments uniramous, subchelate, c) thorax seg. #2 with large subchela, d) moveable rostrum, e) gills on pleopods,
11: Eumalacostraca: a) carapace covers head & thorax (primitively)**, b) long muscular abdomen (primitively)**
12: a) carapace not fused with all head & thorax segments**, b) thoracic oostegites form brood chamber, c) pre-juvenile manca stage
13: a) carapace fused dorsally with all head & thorax segments, b) 3 pr. maxillipeds (except euphausids), c) last 5 pr. thoracic limbs uniramous (except euphausids), d) well-developed gills under carapace (except euphausids), e) brood eggs on pleopods (except euphausids)