Crinoids
Crinoids can be tricky to identify if you only have a few segments; only certain segments can be easily identified. However it is easier to identify the Crown. Crinoids are starfish-related animals.
Articulata crinoidea
UPPER CAMBRIAN TO LOWER TRIASSIC. 500-240 MYA
Articulata crinoidea is recognised by it's unique large Calyx. Unlike most Crinoids, it doesn't have a stem; so it would have been washed away with the currents. 35 cm is a decent size for an Articulata crinoidea.
The Calyx bulges out and is rounded. It has a turtle shell effect. The arms are attached underneath.
The Calyx bulges out and is rounded. It has a turtle shell effect. The arms are attached underneath.
Bourgueticrinus
UPPER CRETACEOUS. 80-75 MYA
Bourgueticrinus is identified by it's unique network of stems.
Unlike most Crinoids, it doesn't have any arms but has a network of stems, therefore its size varies.
The Calyx usually fuses together with the closest segment; it is cone-shaped and decreases towards one end. Segments offen fuse with each other and you can't always see the segments clearly.
Unlike most Crinoids, it doesn't have any arms but has a network of stems, therefore its size varies.
The Calyx usually fuses together with the closest segment; it is cone-shaped and decreases towards one end. Segments offen fuse with each other and you can't always see the segments clearly.
Camerata crinoidea
MIDDLE ORDOVICIAN TO PERMIAN. 460-250 MYA
Camerata crinoidea is identified by it's unique 3 mini Calyx. Unlike most Crinoids it's arms conect to the secondary Calyx that conect to the main Calyx. 35 cm is a decent size for a Camerata crinoidea.
The primary Calyx supports 3 mini Calyx, the arms are atached to the mini Calyx. The arm segments give a plaited effect; the arms also have small antennae around the end, giving a fern-like effect. The segment pattern is 1 big one, then 3-8 small ones with even spacing.
The primary Calyx supports 3 mini Calyx, the arms are atached to the mini Calyx. The arm segments give a plaited effect; the arms also have small antennae around the end, giving a fern-like effect. The segment pattern is 1 big one, then 3-8 small ones with even spacing.
Cladids crinoidea
LOWER MISSISSIPPIAN TO UPPER MISSISSIPPIAN.
359-318 MYA
Cladids crinoidea is recognised by it's unique large number of arms.
30 cm is a decent size for a Cladids crinoidea.
The Calyx is very small and semi-circle shape. It has many arms that have a turtle shell effect. The segments are rounded and are very close together.
30 cm is a decent size for a Cladids crinoidea.
The Calyx is very small and semi-circle shape. It has many arms that have a turtle shell effect. The segments are rounded and are very close together.
Disparida crinoidea
MIDDLE ORDOVICIAN TO UPPER MISSISSIPPIAN. 460-318 MYA
Disparida crinoidea is recognised by it's unique tube-like arms. 25 cm is a decent size for a Disparida crinoidea.
The Calyx is cone-shaped. The arms are tube-like and the arm segments are very thin (it can be mistaken for Chain coral). The segments have a dotty texture.
The Calyx is cone-shaped. The arms are tube-like and the arm segments are very thin (it can be mistaken for Chain coral). The segments have a dotty texture.
Encrinus
MIDDLE TRIASSIC. 230-220 MYA
Encrinus is recognised by it's unique twin-effect arm segments. Encrinus is the most famous crinoid. 30 cm is a decent size for an Encrinus.
Where the arm meets the Calyx there is a zig-zag patten. The arms start with a long thin tube that goes into segments; the segments have a score-like line down it, the arm segments are very thin.
Where the arm meets the Calyx there is a zig-zag patten. The arms start with a long thin tube that goes into segments; the segments have a score-like line down it, the arm segments are very thin.
Eucalyptocrinites
MIDDLE SILURIAN TO MIDDLE DEVONIAN. 420-390 MYA
Eucalyptocrinites is recognised by it's unique scored, wide arms.
15 cm is a decent size for an Eucalyptocrinites.
The calyx is very wide and semi-circle shaped. It has very wide arms that divide into two and each sub-divides further into two more. Segments are rounded and even.
15 cm is a decent size for an Eucalyptocrinites.
The calyx is very wide and semi-circle shaped. It has very wide arms that divide into two and each sub-divides further into two more. Segments are rounded and even.
Flexibilia
LOWER ORDOVICIAN TO UPPER PERMIAN. 498-350 MYA
Flexibilia is recognised by it's unique dividing arms.
10 cm is a decent size for a Flexibilia.
The Calyx divides into three, then those sub-divide into two, then the arms sub-divide into two more. The segments are very thin and the spaces are large.
10 cm is a decent size for a Flexibilia.
The Calyx divides into three, then those sub-divide into two, then the arms sub-divide into two more. The segments are very thin and the spaces are large.
Marsupites
UPPER CRETACEOUS. 85-80 MYA
Marsupites is recognised by it's unique dividing arms. Unlike most Crinoids it doesn't have a stem, so would have drifted with the currents.
15 cm is a decent size for a Marsupites.
The Calyx is covered by hexagonal segments. The arms divide into two.
15 cm is a decent size for a Marsupites.
The Calyx is covered by hexagonal segments. The arms divide into two.
Saccocoma
MIDDLE JURASSIC TO MIDDLE CRETACEOUS. 160-70 MYA
Saccocoma is recognised by it's unique dividing arms. Unlike most crinoids it doesn't have a stem.
15 cm is a decent size for a Saccocoma.
The Calyx is circular-shaped. The arms give a Fern effect (antennae), curling at the end.
15 cm is a decent size for a Saccocoma.
The Calyx is circular-shaped. The arms give a Fern effect (antennae), curling at the end.
