Texas Ammonites

[Last updated 2 Feb 2024]

Phylum: Mollusca (Mollusks)

Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
(ammonites)

Cretaceous Period (click for Pennsylvanian Period)

Family: Collignoniceratidae
Genus: Prionocyclus

Prionocyclus sp.

Strata: Eagle Ford Group (upper)
Period: Cretaceous
Grayson Co., TX. Mar. 22, 2009.

Family: Placenticeratidae
Genus: Placenticeras

Placenticeras sp. Strata: Eagle Ford Group Period: Cretaceous Denton Co., TX. 2007.	Placenticeras sp. Strata: Eagle Ford Group Period: Cretaceous Texas. Dallas Museum NH.
Placenticeras sp. Strata: Eagle Ford Group Period: Cretaceous Dallas Co., TX. 2005-2006	Placenticeras sp. (split) [+] Formation: Eagle Ford Group Period: Cretaceous Dallas, TX. 2006.
Placenticeras sp. Strata: Eagle Ford Group Period: Cretaceous Collin Co., TX. 4 Jun 2023.	Placenticeras sp. Strata: Eagle Ford Group Period: Cretaceous Collin Co., TX. 29 April 2017.
Placenticeras sp. Strata: Eagle Ford Group Period: Cretaceous Collin Co., TX. 30 Sep 2018.

Family: Acanthoceratidae
Genus: Calycoceras

Calycoceras sp. Strata: Woodbine Period: Cretaceous (95 mya) Tarrant Co., TX.	Calycoceras sp. Strata: Woodbine Period: Cretaceous (95 mya) Tarrant Co., TX. [by Mercer B]
This large block crumbled to pieces after drying. :-( Strata: Woodbine Period: Cretaceous (95 mya) Tarrant Co., TX. 8 Aug 2018.

Family: Acanthoceratidae
Genus: Metoicoceras

Metoicoceras sp. Strata: Eagle Ford Group Period: Cretaceous (94 mya) Dallas Co., TX. Feb. 24, 2007.	Metoicoceras sp. Strata: Eagle Ford Group Period: Cretaceous (94 mya) Dallas Co., TX. Dallas museum??
Metoicoceras sp. Strata: Eagle Ford Group Period: Cretaceous (94 mya) Dallas Co., TX. 22 June 2021.	?? Strata: Eagle Ford Group Period: Cretaceous Denton Co., TX. 2007.
Metoicoceras sp. Strata: Eagle Ford Group Period: Cretaceous (94 mya) Dallas Co., TX. 22 June 2021.	Metoicoceras sp. Strata: Eagle Ford Group Period: Cretaceous Collin Co., TX. 29 April 2017.

Family: unknown
Genus: unknown

Unknown ammonite

Strata: Eagle Ford Group
Period: Cretaceous
Denton Co., TX. 30 Sep 2018

Unknown ammonite

Strata: Eagle Ford Group
Period: Cretaceous
Denton Co., TX. 1 Aug 2021

Unknown ammonite

Strata: Eagle Ford Group
Period: Cretaceous
Collin Co., TX. 29 April 2017.

Family: Acanthoceratidae
Genus: Tarrantoceras

Tarrantoceras sp.

Strata: Eagle Ford Group
Period: Cretaceous
Denton Co., TX. Nov. 10, 2007.

Family: Acanthoceratidae
Genus: Mantelliceras

Mantelliceras brazoense

Strata: Del Rio
Period: Cretaceous (98 mya)
McLennan Co., TX. Nov. 17, 2007.

unknown ammonite

Formation: Pawpaw Shale
Period: Cretaceous (98 mya)
Tarrant Co., TX. July 4, 2008.

Family: Desmoceratidae
Genus: Desmoceras

Desmoceras sp.

Strata: Eagle Ford Group
Period: Cretaceous
Dallas co.?, TX. [by Shawn H]

Desmoceras sp.

Strata: Eagle Ford Group
Period: Cretaceous
Dallas co.?, TX. [by Shawn H]

Family: Lyelliceratidae
Genus: Stoliczkaia

Stoliczkaia scotti ?? [+] Formation: Pawpaw Shale Period: Cretaceous (98 mya) Tarrant Co., TX. Nov. 14, 2008.	Stoliczkaia scotti ?? [same] [+] Formation: Pawpaw Shale Period: Cretaceous (98 mya) Tarrant Co., TX. Nov. 14, 2008.
Stoliczkaia ammonite? Formation: Pawpaw Shale Period: Cretaceous (98 mya) Tarrant Co., TX. July 31, 2008.

Family: Engonoceratidae
Genus: Engonoceras

Engonoceras serpintinum Strata: Pawpaw Shale Period: Cretaceous (98 mya) Denton Co., TX. Sep. 8, 2007.	Engonoceras serpintinum Formation: Pawpaw Shale Period: Cretaceous (98 mya) Tarrant Co., TX. March 16, 2008.
Engonoceras serpintinum Strata: Pawpaw Shale Period: Cretaceous (98 mya) Tarrant Co., TX. Feb. 18, 2007.	Engonoceras stolleyi (?) Strata: Goodland Limestone Period: Cretaceous (103-105 mya) Denton Co., TX. Aug. 18, 2008.
Engonoceras pierdenale (?) Strata: Glen Rose Limestone Period: Cretaceous (108-113 mya) Glen Rose, TX. Oct. 2006 [by Roz M]	Engonoceras sp. [+] Strata: Goodland Limestone Period: Cretaceous (103-105 mya) Tarrant Co., TX. 2005
Engonoceras serpintinum Strata: Pawpaw Shale Period: Cretaceous (98 mya) Tarrant Co., TX. 1 Nov 2015	Engonoceras serpintinum Strata: Pawpaw Shale Period: Cretaceous (98 mya) Tarrant Co., TX. 31 Jan 2021.
Engonoceras serpintinum Strata: Pawpaw Shale Period: Cretaceous (98 mya) Tarrant Co., TX. 31 Jan 2021.	Engonoceras serpintinum Strata: Pawpaw Sh. Period: Cretaceous Loc: Denton Co., TX. 20 Sep 2021.

Family: Engonoceratidae
Genus: Metengonoceras

Metengonoceras sp.

Strata: Mainstreet / Grayson Fm.
Period: Cretaceous
Tarrant Co., TX. May 19, 2013.

Metengonoceras sp.

Strata: Mainstreet / Grayson Fm.
Period: Cretaceous
Tarrant Co., TX. 24 April 2017

Family: Brancoceratidae
Genus: Mortoniceras

Mortoniceras equidistans [+] Formation: Duck Creek Fm. Period: Cretaceous (100-101 mya) Tarrant Co., TX.	Mortoniceras sp. [+] Strata: Fort Worth Limestone Period: Cretaceous (100-101 mya) Tarrant Co., TX. 2010.
Mortoniceras sp. ? (right) Formation: Duck Creek Fm. Period: Cretaceous (100-101 mya) Tarrant Co., TX. Dec. 15, 2007.	Mortoniceras sp. [+] Strata: Weno Period: Cretaceous (98 mya) Tarrant Co., TX. May 19, 2013.
Mortoniceras sp. ammonite Strata: Weno Period: Cretaceous (98 mya) Tarrant Co., TX. Apr. 16, 2010.	Mortoniceras sp. Formation: Duck Creek Fm. Period: Cretaceous (100-101 mya) Tarrant Co., TX. 2005
Mortoniceras (Angolaites) sp. [formerly Drakeoceras] Strata: Fort Worth? Period: Cretaceous (100 mya) Fort Worth, TX.	Mortoniceras (Angolaites) sp. [+] [formerly Drakeoceras] Strata: Fort Worth? Period: Cretaceous (100 mya) Tarrant Co., TX. Sep. 9, 2007.
Mortoniceras (Angolaites) sp. [formerly Drakeoceras] Strata: Fort Worth Period: Cretaceous Tarrant Co., TX. July 7, 2007.	Mortoniceras sp. [+] Strata: Weno Limestone Period: Cretaceous (98 mya) Tarrant Co., TX. Aug. 15, 2009.
Strata: Fort Worth? Period: Cretaceous (100 mya) Fort Worth, TX.	A cache of ammonites found close together. Formation: Duck Creek Period: Cretaceous (100-101 mya) Tarrant Co., TX. no date
Drakeoceras was named by Young (1957). It's type is Drakeoceras drakei. It was synonymized with Angolaites by Kennedy et al. (1998).

Family: Brancoceratidae
Subfamily: Mojsisovicziinae
Genus: Oxytropidoceras

Oxytropidoceras sp. Strata: Goodland Limestone Period: Cretaceous (103-105 mya) Tarrant Co., TX.	Oxytropidoceras sp. (view of ribs) [+] Strata: Goodland Limestone Period: Cretaceous (103-105 mya) Tarrant Co., TX.	Oxytropidoceras sp. Strata: Goodland Limestone Period: Cretaceous (103-105 mya) Denton Co., TX. 7 Sep 2024.
Manuiceras sp.? [+] Strata: Goodland Limestone Period: Cretaceous (103-105 mya) Tarrant Co., TX. 2005	Manuiceras sp.? Strata: Goodland Limestone Period: Cretaceous (103-105 mya) Tarrant Co., TX.	Oxytropidoceras sp. cast Strata: Kiamichi Period: Cretaceous (102 mya) Tarrant Co., TX. April 22, 2012.
Oxytropidoceras sp. cast Strata: Goodland Limestone Period: Cretaceous (103-105 mya) Denton Co., TX. 2007.	Oxytropidoceras sp. cast Strata: Kiamichi Period: Cretaceous (102 mya) Tarrant Co., TX. April 14, 2013.
Oxytropidoceras diazi [Adkinsites] Strata: Kiamichi Period: Cretaceous (102 mya) Tarrant Co., TX. 20 May 2019	Oxytropidoceras diazi [Adkinsites] Strata: Kiamichi Period: Cretaceous (102 mya) Tarrant Co., TX. 2005	?? Strata: Goodland Limestone? Period: Cretaceous (103-105 mya) Tarrant Co., TX. no date

Family: Pachydiscidae
Genus: Eopachydiscus

Eopachydiscus marcianus Strata: Duck Creek Period: Cretaceous (100-101 mya) Tarrant Co., TX. no date	Eopachydiscus marcianus Strata: Duck Creek Period: Cretaceous (100-101 mya) Tarrant Co., TX. no date	Eopachydiscus marcianus Strata: Duck Creek Period: Cretaceous (100-101 mya) Tarrant Co., TX. no date
Eopachydiscus sp. Strata: Duck Creek Period: Cretaceous (100-101 mya) Tarrant Co., TX. no date	Eopachydiscus sp. Formation: Duck Creek Period: Cretaceous (100-101 mya) Tarrant Co., TX. March 2007.