Menu
Log in

Texas Pennsylvanian Fossils

Dedicated to the Study of Pennsylvanian Fossils, Sponsored by Members of the Dallas Paleontological Society


Log in

Bryozoans 

Bryozoans are a group of microscopic marine invertebrates that originated in the Ordovician and still inhabit the oceans today.  They are colonial animals living within a calcareous skeleton which is generally what fossilizes.  In the Paleozoic, the bryozoans were a dominant group in many of the world’s seas.  The skeletons primarily existed attached to the seafloor, or something on it, and come in a wide variety of shapes; from simple sticks to elaborate lacy, mesh-like structures.

In the Finis Shale, bryozoans constitute one of the larger fractions of the fossil fauna.  They are found almost exclusively as small fragments of colonies, very seldom exceeding more than a few centimeters in size.  There are over two dozen species recognized but identifying them to species, or even genus, generally can only be done by microscopic examination of thin sections.  We are fortunate to have a recently published work on the Finis bryozoans which aids in identification of hand samples.  The genera Polypora and Cystodictya are common in most samples; most of the others are much rarer.   A special thanks goes to Dr. Andrej Ernst, lead author of the 2023 paper on Finis bryozoans, who provided invaluable identifications, comments, and feedback on most of our samples.

----------------------------------------------------------------------------------------------------------------------------------------------------

Scroll through images or click to enlarge.  Fossils are grouped taxonomically and in phylogenetic order as on Bryozoa.net.

Collections are from Mike DeBrock (MD), Josh Hanley (JH), Dr. Peter Holterhoff (PH), Mark McKinzie (MM), John McLeod (JM), Dr. Ben Neuman (BN), Bob Williams (BW), Sveta Earnest (SE), Rodney Wise (RW), and Jeremy Faulder (JF)..  

All scales are shown in millimeters unless otherwise noted.


Images

Taxonomy/Stratigraphy/
Location/Collection

Images

Taxonomy/Stratigraphy/
Location/Collection

Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Cryptostomata

Family: Rhomboporidae

Genus: Rhombopora

Species: R. lepidodendroides

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: BW, MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Cryptostomata

Family: Hyphasmoporidae

Genus: Streblotrypa

Species: S. multipora

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: BW, MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Cystoporata

Family: Fistuliporidae

Genus: Fistulipora

Species: F. incrustans

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: SE


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Cystoporata

Family: Fistuliporinae

Genus: Fistulipora

Species: F. nodulifera

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: MD, MM


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Cystoporata

Family: Fistuliporidae

Genus: Fistulipora

Species: F. regularis

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: 


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Cystoporata

Family: Fistuliporidae

Genus: Fistulipora

Species: F. vaccula

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: SE


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Cystoporata

Family: Fistuliporidae

Genus: Eridopora 

Species: E. beilensis

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: MM


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Cystoporata

Family: Cystodictyonidae

Genus: Cystodictya

Species: C. fomosa

Finis Shale, Graham Formation

LCCem Jacksboro, TX

Collection: MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Cystoporata

Family: Goniocladiidae

Genus: Goniocladia

Species: G. grahamensis

Finis Shale, Graham Formation

LCCem, Jacksboro, TX

Collection: MD, SE


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Trepostomida

Family: Dyscritellidae

Genus: Dyscritella

Species: D. felixi

Finis Shale, Graham Formation

LCCem, Jacksboro, TX

Collection: MD, BW


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Trepostomida

Family: Stenoporidae

Genus: Tabulipora

Species: Tcava

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: 


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Trepostomida

Family: Stenoporidae

Genus: Tabulipora

Species: T. plummeri

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: MM


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Trepostomata

Family: Heterotrypidae

Genus:  Leioclema 

Species: L. hirsutum

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: MM


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Trepostomida

Family: Stenoporidae

Genus: Tabulipora

Species: T. carbonaria

Finis Shale, Graham Formation

Lost Creek Dam and Cemetery, Jacksboro, TX

Collection: MM, RW


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Chainodictyonidae

Genus: Chainodictyon

Species: C. minor

Finis Shale, Graham Formation

LCCem, Jacksboro, TX

Collection: MD, BW


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Chainodictyonidae

Genus: Rhombocladia

Species: R. delicata

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: BW, MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Fenestellidae

Genus: Acupipora

Species: A. elliptica

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Fenestellidae

Genus: Cavernella

Species: C. praecavifera

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: 


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Fenstellidae

Genus: Fabifenestella

Species: F. compactilis

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: 


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Fenestellidae

Genus: Fenestella

Species: F. mimica

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Fenestellidae

Genus: Laxifenestella

Species: L. texana

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: MD, MM


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Fenestellidae

Genus: Laxifenestella 

Species: L. placida

Finis Shale, Graham Formation

LCCem, Jacksboro, TX

Collection: MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Polyporidae

Genus:  Polypora 

Species: P. arata

Finis Shale, Graham Formation

LCCem, Jacksboro, TX

Collection: SE, MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Polyporidae

Genus:  Polypora aff.

Species: P. hexagona

Finis Shale, Graham Formation

LCCem, Jacksboro, TX

Collection: MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Polyporidae

Genus:  Polypora

Species: P. sigillaria

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Polyporidae

Genus:  Polypora

Species: P. triangularis

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: MM, MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Polyporidae

Genus:  Polypora

Species: P. valida

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Septoporidae

Genus: Septopora

Species: S. blanda

Finis Shale, Graham Formation

Lost Creek Dam, Jacksboro, TX

Collection: BW, MD, JF


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Septoporidae

Genus: Thamniscus

Species: T. octonarius

Finis Shale, Graham Formation

Lost Creek Cemetery, Jacksboro, TX

Collection: MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Acanthocladiidae

Genus:  Penniretepora

Species: P. flexistriata

Finis Shale, Graham Formation

LCCem, Jacksboro, TX

Collection: MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: Fenestrata

Family: Acanthocladiidae

Genus:  Penniretepora

Species: P. oculata

Finis Shale, Graham Formation

LCCem, Jacksboro, TX

Collection: MD


Kingdom: Animalia

Phylum: Bryozoa

Class: Stenolaemata

Order: 

Family: 

Genus: 

Desc: Bryozoan Holdfasts

Finis Shale, Graham Formation

Lost Creek Cem., Jacksboro, TX

Collection: MD, BN

Note: A selection of Bryozoan attachment features


Kingdom: Animalia

Phylum: Bryozoa

Class: 

Order: 

Family: 

Genus: 

Desc: Bryozoan Growths

Finis Shale, Graham Formation

Lost Creek Cem., Jacksboro, TX

Collection: MD

Note: Peculiar growths found on bryozoans


©Dallas Paleontological Society 2025, All Rights Reserved

The Dallas Paleontological Society is a 501 (c) 3 nonprofit organization.

Privacy Policy        Terms of Use   

Dallas Paleontological Society 
P.O. Box 223846 Dallas, Texas 75222-3846

Powered by Wild Apricot Membership Software