(water flea)	(gooseneck barnacle)	Subphylum CRUSTACEA (tree/traits: Brusca & Brusca 2003 p. 580)	(mantis shrimp)	(amphipod)
	(calanoid copepod)		(lobster)

       ====1============================= Cl. Remipedia
<<==C==|
       |   ===3========================== Cl. Cephalocarida
       =2==|
           |   ==5======================= Cl. Branchiopoda (fairy shrimp, water fleas, etc.)
           =4==|
               |   ==7=================== Cl. Maxillopoda (copepod, ostracod, barnacle, etc.)
               ==6=|
                   |    ==8============== SubCl. Phyllocarida (Or. Leptostraca)
                   =Mal=|
                        |      ==9======= SubCl. Hoplocarida (mantis shrimps)
                        =Eumal=|
                               |    ==11= SupOr. Peracarida (mysids,  amphipods, isopods, etc.)
                               =10==|
                                    ==12= SupOr. Eucarida (krill, shrimps, lobsters, crabs, etc.)

Back to Zool 250 tree for animal phyla or Protostomia

TRAITS SUPPORTING EACH CLADE (** plesiomorphic- a primitive state, not unique to clade):

C= CRUSTACEA: a) two pairs of antennae b) first antennae uniramous** c) second antennae biramous d) mandible is simple (gnathobasic) e) sessile (non-stalked), compound eyes** f) many similar, biramous, phyllopodous thoracic limbs** g) telson with rami h) nauplius larvae 1= Remipedia: a) first antennae biramous b) raptorial mouth appendages c) segment #6= maxilliped d) many similar trunk segments (thorax & abdomen not distinct) with paddle-like biramous legs e) pre-antennal process f) eyes lost 2: a) 3 tagmata (head, thorax, abdomen) b) reduced number of body segments 3= Cephalocarida: a) abdominal appendages lost b) abdomen of 11 segments c) segment #5= leg-like d) compound eyes lost 4: a) large carapace (covers head & thorax) b) abdomen has fewer than 9 segments 5= Branchiopoda: a) maxillae (segments #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= Maxillopoda: a) thorax has fewer than 7 segments b) abdomen has fewer than 5 segments c) unique naupliar eyes & loss of lateral compound eyes d) genital appendages on 1st abdominal somite of male

Mal= Malacostraca: a) thorax of 8 segments with similar limbs b) abdomen of 7 segments + telson c) carapace covers head & thorax** d) first antennae biramous in adult e) stalked eyes in adult f) male gonopore on segment 8, female on segment 6 8= Phyllocarida: a) second antennae uniramous b) abdomen of 7 segments + telson** c) second maxilla resembles thoracic limbs** d) similar, phyllopodous thoracic limbs** Eumal= Eumalacostraca: a) abdomen of 6 segments + telson b) thoracic limbs stenopodous c) long muscular abdomen d) telson lacks rami e) uropods + telson make a tail fan 9= Hoplocarida: a) carapace covers head & 4 thoracic segments b) limbs of first 5 thoracic segments uniramous & subchelate c) thorax segment #2 with very large subchela d) moveable rostrum e) gills on pleopods 10: a) carapace covers head & thorax (primitively)** 11= Peracarida: a) carapace not fused with all head & thorax segments** b) thoracic oostegites form brood chamber c) pre-juvenile manca stage 12= Eucarida: a) carapace fused dorsally with all head & thorax segments b) 3 pair maxillipeds (except euphausiids) c) last 5 pair thoracic limbs uniramous (except euphausiids) d) well-developed gills under carapace (except euphausiids) e) brood eggs on pleopods (except euphausiids)