Welcome to Catnapin's
Fossil Gallery - Echinoid (urchin)
Echinodermata, Echinoidea
(Phylum, Class)
Red text = needs information
Fossil identification by Jo Cox unless otherwise noted
*****************************************************************
|
Echinoids are sea urchins, sand dollars, and heart urchins. The name means spiny skinned. These animals have a shell made up of plates that in life was covered with a leathery skin and spines of various sizes. Most echinoids have a five-armed star decorating the top. A multitude of tube feet help in movement and passing food to the mouth. Their mouth is located on the bottom with five teeth inside the hole, which are rarely found. The second hole is the anus. Paleozoic Echinoid plates are often scattered after death because they were attached by tissue. Most were sea urchins. Sea urchins are ball-shaped, round dome, or thick disk. The mouth is centered on the bottom with the anal opening directly above. Sanddollars are flat and roundish, some have penetrations through the shell. The mouth is off center on bottom with the anal opening. In life they have a velvety coating of spines and hair-like cilia, which help the animal to move and gather food. Heart urchins are bilaterally symmetric domes and roughly heart shaped. The mouth is off center on the bottom. Depending on the type, the anal opening can be on the bottom, top, or side. |
*****************************************************************
Paleozoic
*****************************************************************
Perischoechinoida, Perischoechinoidea
(Order, Subclass)
|
? Period: Pennsylvanian Location: north of Cisco, Texas Collection: Jo Cox Size: 13 mm long |
|
|
Description: a new spine from the top of the Echinoid. It would have grown longer and more ornamental as the animal aged. |
|
|
Archaeocidaris sp. Period: Pennsylvanian Location: ? Collection: Hardin-Simmons University Size: 24 mm long |
|
|
Description: ornamental spine |
|
|
? Period: Pennsylvanian Location: north of Cisco, Texas Collection: Jo Cox Size: ? mm long |
|
|
Description: assorted plates |
|
|
Archaeocidaris sp. Period: Pennsylvanian Location: near Brownwood, Texas Collection: Judie Ostlien Size: 16 mm wide |
|
|
Description: spine attachment plate |
|
*****************************************************************
Cretaceous
*****************************************************************
Phymosomatoida
(Order)
|
Phymosoma texanum Common Name: sea urchin Period: lower Cretaceous, Fredericksburg group, "Walnut / Comanche Peak Undifferentiated" formation Location: Taylor Co., Texas -- White Mines Gravel Collection:< Jo Cox Size: 38 mm wide |
|
*****************************************************************
Holasteroida
(Order)
|
Holaster simplex Common Name: heart urchin Period: lower Cretaceous, Washita group, "Duck Creek / Ft. Worth Undifferentiated" formation Location: Denton Co., Texas Collection: Abilene Christian University Natural History Collection Size: 57 mm wide |
|
*****************************************************************
Hemicidaroida
(Order)
|
Polydiadem texanum Common Name: sea urchin Period: lower Cretaceous, Fredericksburg group, "Walnut / Comanche Peak Undifferentiated" formation Location: Taylor Co., Texas -- "White Mines Gravel" Collection: Jo Cox Size: 15 mm wide |
|
*****************************************************************
Salenioida
(Order)
|
Salenia mexicana Common Name: sea urchin Period: lower Cretaceous, Fredericksburg group, "Walnut / Comanche Peak Undifferentiated" formation Location: Taylor Co., Texas -- "White Mines Gravel" Collection: Jo Cox Size: 17 mm Dia. |
|
|
Salenia texana Common Name: sea urchin Period: lower Cretaceous, Fredericksburg group, "Walnut / Comanche Peak Undifferentiated" formation Location: Taylor Co., Texas, -- "White Mines Gravel" Collection: Jo Cox Size: 19 mm Dia. |
|
*****************************************************************
Spatangoida
(Order)
|
Heteraster adkinsi Common Name: heart urchin Period: lower Cretaceous, Fredericksburg group, "Walnut / Comanche Peak Undifferentiated" formation Location: Taylor Co., Texas, -- "White Mines Gravel" Collection: Jo Cox Size: 27 mm wide |
|
|
Macraster elegans Common Name: heart urchin Period: lower Cretaceous, Fort Worth formation Location: Tarrant Co., Texas Collection: Abilene Christian University Natural History Collection Size: 50 mm wide |
|
|
Holectypus engerrandi Common Name: sea urchin Period: lower Cretaceous, Fredericksburg group, "Walnut / Comanche Peak Undifferentiated" formation Location: Taylor Co., Texas -- "White Mines Gravel" Collection: Judie Ostlien Size: 25 mm wide |
|
|
Description: not typical sea urchin, not round, anal opening is on bottom |
|
|
Holectypus engerrandi Common Name: sea urchin Period: lower Cretaceous, Fredericksburg group, "Walnut / Comanche Peak Undifferentiated" formation Location: Taylor Co., Texas -- "White Mines Gravel" Collection: Hardin-Simmons University Size: 18 mm wide |
|
|
Description: not typical sea urchin, not round, anal opening is on bottom |
|
*****************************************************************
