1a. Echinoderms with distinguishable radiating arms; without oral tentacles.
Step 3. 2
1b. Echinoderms without distinguishable radiating arms; with or without oral tentacles.
Step 35. 34
55 possible taxa remaining show common names
- Amphipholis squamata
- Amphiura brachiata
- Amphiura chiajei
- Amphiura filiformis
- Amphiura securigera
- Anseropoda placenta
- Antedon bifida
- Antedon petasus
- Asterias rubens
- Astropecten irregularis
- Brissopsis lyrifera
- Crossaster papposus
- Cucumaria frondosa
- Echinocardium cordatum
- Echinocardium flavescens
- Echinocyamus pusillus
- Echinus acutus
- Echinus elegans
- Echinus esculentus
- Henricia sanguinolenta
- Hippasteria phrygiana
- Labidoplax digitata
- Leptasterias muelleri
- Leptometra celtica
- Leptopentacta elongata
- Leptosynapta bergensis
- Leptosynapta decaria
- Leptosynapta inhaerens
- Leptosynapta minuta
- Luidia ciliaris
- Luidia sarsi
- Marthasterias glacialis
- Neopentadactyla mixta
- Ocnus planci
- Ophiactis balli
- Ophiocomina nigra
- Ophiopholis aculeata
- Ophiothrix fragilis
- Ophiura affinis
- Ophiura albida
- Ophiura ophiura
- Ophiura robusta
- Paracucumaria hyndmani
- Porania pulvillus
- Psammechinus miliaris
- Pseudothyone raphanus
- Psolus phantapus
- Rhabdomolgus ruber
- Solaster endeca
- Spatangus purpureus
- Stichastrella rosea
- Thyone fusus
- Thyone inermis
- Thyonidium drummondii
- Thyonidium hyalinum
Decision path