blastoid
Extinct sea bud
A blastoid is an extinct marine animal related to sea lilies and starfish, found as fossils from the Paleozoic era.
The name refers to the bud-like shape of its body.
In biology, blastoid also describes anything resembling or relating to a blastula—an early stage of embryonic development.
Minute skeletal structures
- calciteCrystalline calcium carbonate
- endoskeletonBody's inner framework
- podiaPlural speaking platforms
- thecaProtective biological envelope
deltoid · radial · lancet · spiracle · calyx · stem · holdfast · plate
Invariance under transformation
- calyxCollective sepals encircling petals
- thecaProtective biological envelope
- spiraclesExternal respiratory apertures
- deltoidShoulder's main muscle
radial · lancet · stem · oral · globular · ovoid · ornament · plate
Paleozoic period, mid-range
- DevonianGeologic period, 419-359 million years ago
- CarboniferousCoal-depositing geological period
- MississippianNative of a southern state
- PermianLate Paleozoic geological period
Ordovician · extinction · Paleozoic · fossilization · brachiopods · trilobites · reef · stratigraphy
Becoming rock-like
- impressionEffect on the mind
- sedimentParticles settling in liquid
- limestoneCarbonate sedimentary rock
- shaleCompacted clay sediment
preservation · excavation · specimen · mold · cast · calcified · burial · stratigraphy
ossicles
Minute skeletal structures
- calciteCrystalline calcium carbonate
- endoskeletonBody's inner framework
- podiaPlural speaking platforms
theca · deltoid · radial · lancet · spiracle · calyx · stem · holdfast · plate · oral
symmetry
Invariance under transformation
- calyxCollective sepals encircling petals
- thecaProtective biological envelope
- spiraclesExternal respiratory apertures
deltoid · radial · lancet · stem · oral · globular · ovoid · ornament · plate · suture
Silurian
Paleozoic period, mid-range
- DevonianGeologic period, 419-359 million years ago
- CarboniferousCoal-depositing geological period
- MississippianNative of a southern state
Permian · Ordovician · extinction · Paleozoic · fossilization · brachiopods · trilobites · reef · stratigraphy · paleoecology
petrification
Becoming rock-like
- impressionEffect on the mind
- sedimentParticles settling in liquid
- limestoneCarbonate sedimentary rock
shale · preservation · excavation · specimen · mold · cast · calcified · burial · stratigraphy · outcrop
blastoidsea star
Five-armed marine invertebrate
starfish · sea urchin · sea cucumber · brittle star · sand dollar