Uploaded by Nathan Riley

Animal Diversity Project

By Tony Tedesco, Noah Roberts, Lucas Tekle
Characteristics and Behaviors
● One of the most diverse groups of animals
● All have an exoskeleton
● They have evolved from eurypterids and
● They all came from marine animals
● Some of live in the water some live on land
● They are omnivores
Introductory Information
● Chelicerates are sea spiders and
horseshoe crabs scorpions, mites, spiders
● Belong to the Arachnida
● They often live under logs, stones, leaves,
mold, and other sorts of vegetation
● However some live in saltwater as well as
● There are 1300 species of sea spiders
● They have six pairs of appendages
● It has 2 different body segments
● Were originally predators, but has diversified
to use all the major feeding strategies:
predation, herbivory, scavenging, and eating
decaying organic matter
● The appendages or chelicerae are usually
modified into fangs or pincers
● They constantly patrol large areas
● They move at right angles
● It sucks the liquid out of the prey as food
● Has an Exoskeleton
● They can hear, but they can't distinguish
between noises because they can't sense
frequencies (they only hear noise).
● Some participate in parental care
● They also have some very unique mating
● They can be deadly to insects, but the great
majority are are harmless to vertebrates
● Air breathing chelicerates use internal but
usually indirect fertilization
● Most lay eggs that hatch as what look like
miniature adults
Environment and Evolution
● They live in several environments
depending on the species
● These include: beneath stone and logs, in
leaf mold, and in vegetation
● There are a few that live in freshwater
and the sea
● They are known to have evolved from a
common ancestor of eurypterids or
● Some of the chelicerates have evolved to
live in aquatic environments such as sea
spiders, horseshoe crabs, and water
● Most of the species complete
development with four pairs of legs, but
some some have five or six pairs
Ecological Analysis
● Chelicerates include species such as insects
and fishes.
● Examples of them are scorpions, mites,
spiders, and horseshoe crabs.
● They all came from marine animals during
the Late Ordovician period.
● An estimated amount of 77,000 air breathing
chelicerates have been identified, however,
there are 500,000 species that are yet to be
● There may be 130,000 undescribed species
of spiders
To conclude, Chelicerates are a distinct animal
since they are on the older end of the
evolutionary scale. Chelicerates come in a
variety of shapes and sizes, and each one is
distinct from the others. They devour both
animals and plants. They can also survive in
practically any environment and under the
most adverse conditions. This is why they are
unique and one of the world's oldest animals.