Arachnida
Other Chelicerates
Everything Echinodermata
Asterozoa
Echinozoa
Chordata
100
These arachnids have a segmented tail ending in a stinger.
What are scorpions?
100
Organisms in the Order Xiphosura are commonly called this.
What are horseshoe crabs?
100
The phylum name is derived from this Latin phrase.
What is "spiny skin?"
100
Members of Class Ophiuroidea - the most species-rich class of echinoderms - are commonly called these.
What are brittle stars?
100
The main food source of most echinoids is this.
What is algae?
100
Cephalochordates are commonly called lancelets or this.
What is amphioxus?
200
Acari is the informal name given to these organisms.
What are ticks and mites?
200
Organisms in Class Pycnogonida are commonly called this.
What are sea spiders?
200
During embryonic development, the blastopore becomes the anus, rather than mouth, which is why echinoderms are in this group.
What are deuterostomes?
200
Sea stars have two of these organs, which help them feed on clams and other hard-shelled prey.
What is stomach?
200
This global ocean phenomenon could impede sea urchin calcification, but it could also boost shell growth.
What is ocean acidification?
200
Common name for these chordates:
What are salps?
300
Common name of the species shown here:
What is lone star tick?
300
This chelicerata body segment may also be called a cephalothorax.
What is the prosoma?
300
These structures are used to walk and feed.
What are tube feet?
300
The later stage larval form of sea stars is called this.
What is brachiolaria?
300
This is another name for the shell of sea urchins and sand dollars.
What is the test?
300
Subphylum Urochordata is now named this.
What is Tunicata?
400
This is the life stage of chiggers (AKA harvest mites) that feeds on human skin.
What is larval stage?
400
Opisthosoma is a hard word to remember. You can also call simply call this lower cheliceran body segment this.
What is the abdomen?
400
This is the most basal class in the phylum.
What is Class Crinoidea?
400
Sunflower sea stars usually have this important role in their ecological community.
What is a keystone predator?
400
Sea cucumbers expel these sticky, toxic structures from their anus.
What are Cuvierian tubules?
400
This is the largest, most species-rich class of sea squirts.
What are ascidians (Class Ascidiacea)?
500
These are the two key traits that all spiders have.
What are spinnerets and venom-delivering fangs?
500
Horseshoe crabs are the only chelicerates that have these structures, in addition to ocelli.
What are compound eyes?
500
Most echinoderms have an intake pore for their water vascular system called this.
What is the madreporite?
500
Common name of the species shown here:
What is the crown-of-thorns starfish?
500
The name of a complex, jawed structure found in sea urchins.
What is Aristotle's lantern?
500
All chordates have these four synapomorphies.
What are a notochord, nerve cord, pharyngeal gill slits, and post-anal tail?