small translucent lancet-shaped burrowing marine animal
anomalops
Noun
fish having a luminous organ beneath eye
ascidian
Noun
minute sedentary marine invertebrate having a saclike body with siphons through which water enters and leaves
abortus
Noun
a human fetus whose weight is less than 0.5 kilogram when removed or expelled from the mother's body
appendicularia
Noun
free-swimming tadpole-shaped pelagic tunicate resembling larvae of other tunicates
ascidian tadpole
Noun
free-swimming larva of ascidians
archenteron
Noun
central cavity of the gastrula
amniote
Noun
any member of the Amniota
amnion
Noun
thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)
allantois
Noun
the vascular fetal membrane that lies below the chorion and develops from the hindgut in many embryonic higher vertebrates (reptiles, birds and mammals)
aquatic vertebrate
Noun
animal living wholly or chiefly in or on water
angel shark
Noun
sharks with broad flat bodies and winglike pectoral fins but that swim the way sharks do
angelfish
Noun
sharks with broad flat bodies and winglike pectoral fins but that swim the way sharks do
angelfish
Noun
deep-bodied disk-shaped food fish of warmer western Atlantic coastal waters
angelfish
Noun
a butterfly fish of the genus Pomacanthus
agnathan
Noun
eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct forms
anaspid
Noun
extinct small freshwater jawless fish usually having a heterocercal tail and an armored head
amniotic sac
Noun
thin innermost membranous sac enclosing the developing embryo of higher vertebrates
amnios
Noun
thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)
aepyornis
Noun
huge (to 9 ft.) extinct flightless bird of Madagascar
anomalopteryx
Noun
the smallest moa
archaeopteryx
Noun
extinct primitive toothed bird of the Jurassic period having a long feathered tail and hollow bones
archeopteryx
Noun
extinct primitive toothed bird of the Jurassic period having a long feathered tail and hollow bones
archaeornis
Noun
extinct primitive toothed bird with a long feathered tail and three free clawed digits on each wing
accentor
Noun
small sparrow-like songbird of mountainous regions of Eurasia
avadavat
Noun
red Asian weaverbirds often kept as cage birds
amadavat
Noun
red Asian weaverbirds often kept as cage birds
antbird
Noun
any of various dull-colored South American birds that feeding on ants some following army ant swarms
ant bird
Noun
any of various dull-colored South American birds that feeding on ants some following army ant swarms
ant thrush
Noun
a kind of antbird
ant shrike
Noun
antbirds superficially resembling shrikes
amphibia
Noun
the class of vertebrates that live on land but breed in water
amphibian family
Noun
any family of amphibians
amphibian genus
Noun
any genus of amphibians
arboreal salamander
Noun
yellow-spotted brown salamander of California woodlands
alpine salamander
Noun
ovoviviparous amphibian of the Alps
amphiuma
Noun
aquatic eel-shaped salamander having two pairs of very small feet
ambystomid
Noun
small to moderate-sized terrestrial or semiaquatic New World salamander
ambystomid salamander
Noun
small to moderate-sized terrestrial or semiaquatic New World salamander
axolotl
Noun
larval salamander of mountain lakes of Mexico that usually lives without metamorphosing
alligator snapping turtle
Noun
large species having three ridges on its back
alligator snapper
Noun
large species having three ridges on its back
anapsid
Noun
primitive reptile having no opening in the temporal region of the skull
anapsid reptile
Noun
primitive reptile having no opening in the temporal region of the skull
agua
Noun
largest known toad species
agua toad
Noun
largest known toad species
archosaurian reptile
Noun
extinct reptiles including: dinosaurs
anguid lizard
Noun
any of a small family of lizards widely distributed in warm areas
anole
Noun
small arboreal tropical American insectivorous lizards with the ability to change skin color