TRILOBITES:
ENVIRONMENT
NEWS:
Trilobite fossils from upstate New York reveal extra set of legs
WHAT’S
IN THE NEWS?
A new study finds that a trilobite species with
exceptionally well-preserved fossils from upstate New York has an additional
set of legs underneath its head. The research, led by the American Museum of
Natural History and Nanjing University in China, suggests that having a fifth
pair of head appendages might be more widespread among trilobites than once thought.
Trilobites:
Definition:
·
Extinct
marine arthropods from the Paleozoic Era.
·
One
of the earliest-known arthropod groups.
·
First
animals known to have vision.
Time Period:
·
Lived
from the Cambrian Period (~521 million years ago) to the Permian Period (~252
million years ago).
Phylum:
·
Arthropoda
(same as modern insects, crustaceans, and spiders).
Key Features:
·
Three-lobed
body (head, body, tail).
·
Exoskeleton
made of chitin.
·
Segmented
body for movement.
·
Some
had advanced compound eyes with calcite lenses.
Size:
·
Ranged
from a few millimeters to over 70 cm.
Habitat:
·
Marine
organisms, living on the ocean floor or swimming in the water column.
Diet:
·
Varied:
scavengers, predators, filter-feeders.
Arthropods:
Characteristics:
·
Invertebrates
with an exoskeleton, segmented bodies, jointed appendages.
·
Bilateral
symmetry and open circulatory system.
·
Represent
75% of all animal species.
Body
Regions:
·
Head,
thorax, abdomen (some have cephalothorax).
Key Classes:
·
Insects: 3 body parts, 6
legs.
·
Arachnids: 8 legs (spiders,
scorpions).
·
Crustaceans: 2-3 body parts
(crabs, lobsters).
·
Myriapods: Centipedes,
millipedes.
Habitat:
·
Found
in all ecosystems: marine, freshwater, terrestrial.
Significance:
·
Pollinators
(bees), decomposers (termites), food sources (crustaceans), pests (locusts),
disease vectors (mosquitoes).
Examples: Ants, bees, spiders, crabs, lobsters,
centipedes, butterflies