Phylum: Echinodermata

Class: Echinoidea - Echinoids
Irregular echinoids (heart urchins, etc. )

Irregular urchins - " They burrow along the sea floor and bulk-feed on the sediment to extract nutrients. For this reason the radial symmetry inherited from the regulars has been modified; the mouth moving to the front of the animal to collect food and the anus moving to the rear to leave waste behind. "
Cretaceous period:
Hemiaster whitei echinoid Formation: Goodland  Period:  Cretaceous (103-105 mya) Loc: Tarrant co., Tx.  July 4, 2008.	Hemiaster calvini echinoid Formation: Grayson Period:  Cretaceous (95-97 mya) Loc: Tarrant co., Tx.  Aug. 1, 2007.	Hemiaster calvini echinoid Formation: Grayson Period:  Cretaceous (95-97 mya) Loc: Tarrant co., Tx.  Aug. 1, 2007.
Heteraster sp. Formation: Goodland Period:  Cretaceous (c. 103-5 mya) Loc: Tarrant co., Tx.	Heteraster sp. Formation: Goodland Period:  Cretaceous (c. 103-5 mya) Loc: Tarrant co., Tx.	Heteraster sp. Formation: Goodland or Walnut?  Period:  Cretaceous (c. 105 mya) Loc: Tarrant co., Tx.?
Holaster sp.  echinoid Formation: Weno?  Period:  Cretaceous (98 mya) Loc: Denton co., Tx.  Sep. 8, 2007.	Holaster sp. echinoids Formation: Fort Worth? Period:  Cretaceous (100 mya) Loc: Tarrant co., Tx.  Sep. 9, 2007.	Holaster sp. echinoids Formation: Fort Worth? Period:  Cretaceous (100 mya) Loc: Tarrant co., Tx.  Sep. 9, 2007.
Holaster simplex echinoid [+] Formation: Duck Creek (lower) Period:  Cretaceous (100-101 mya) Loc: Tarrant co., Tx. Dimensions: exactly 2" long	Holaster sp. echinoid Formation: Weno?  Period:  Cretaceous (98 mya) Loc: Tarrant co., Tx.  June 17, 2007.	Holaster sp. echinoid Formation: Weno?  Period:  Cretaceous (98 mya) Loc: Tarrant co., Tx.  June 17, 2007.
Macraster sp. echinoid Formation: Duck Creek (lower limestone) Period:  Cretaceous (101 mya) Loc: Tarrant co., Tx.  Aug. 14, 2008.	Macraster sp. echinoid Formation: Duck Creek (lower limestone) Period:  Cretaceous (101 mya) Loc: Tarrant co., Tx.  Aug. 14, 2008.	Macraster sp. echinoid Formation: Fort Worth  Period:  Cretaceous (100 mya) Loc: Tarrant co., Tx.  July 7, 2007.
Macraster washitae echinoid Formation: Duck Creek Period:  Cretaceous (100-101 mya) Loc: Tarrant co., Tx. Dimensions: exactly 3" long	Macraster washitae echinoid Formation: Duck Creek  Period:  Cretaceous (100-101 mya) Loc: Tarrant co., Tx. Dimensions: exactly 3" long	Macraster sp. echinoid [+] Formation: Fort Worth  Period:  Cretaceous (100 mya) Loc: Tarrant co., Tx.  Aug. 2, 2008.
Pseudananchys sp. echinoid   (found by Roz) Formation: Grayson Period:  Cretaceous (95-97 mya) Loc: Tarrant co., Tx.  March 23, 2008.	Pseudananchys sp. echinoid (found by Roz) Formation: Grayson Period:  Cretaceous (95-97 mya) Loc: Tarrant co., Tx.  March 23, 2008.	Pseudananchys sp. echinoid  (found by Linda McCall) Formation: Grayson Period:  Cretaceous (95-97 mya) Loc: Denton co., Tx.  Aug. 16, 2008.
Coenholectypus sp. (Holectypus limitis) Formation: Mainstreet Period:  Cretaceous (97 mya) Loc: Tarrant co., Tx.  Oct. 20, 2007.	Coenholectypus sp. (Holectypus limitis) Formation: Mainstreet Period:  Cretaceous (97 mya) Loc: Tarrant co., Tx.  Oct. 20, 2007.
Lefortia sp. (new?)  Formation: Marlbrook? Period:  Cretaceous  Loc: Arkansas.  July 2007.	Lefortia sp. (new?)  Formation: Marlbrook? Period:  Cretaceous  Loc: Arkansas.  July 2007.