Central Texas Fossils- Species by Formation

[JamieLynn]

Hello all! This is a little photo project I've been working on for a while. When I first started Fossil Hunting I was content to collect whatever. Then I was excited about Identifying what I was finding. The education continued and now I work to identify the geological formations I am collecting in and am able to know what fossils to look for in what areas.  The Pocket Texas Geology website is invaluable for finding out the formation of a specific area (while not 100 percent accurate, it's pretty good). So I wanted to create a post that would help with Central Texas Cretaceous Fossil Identification and this Species by Formation post. There are a couple of great websites for North Texas Fossil ID, but none (that I am aware of) for specifically Central Texas. I am considering Central Texas to be the counties of Hays, Travis, Comal, Blanco, Bexar, Kendell, Williamson, Hill, Burnet, Llano, Bell, Coryell, McLennon and Bosque. 

 

And bear in mind, this is not a comprehensive list of all species found in these formations...still working on THAT! But this is what I have found and ID'd so far. I believe it contains MOST of the more commonly found fossils, plus some uncommon fossils.  If you see a mis-identification, please let me know!  Also, there are more formations than I am presenting, but these have been the most accessible to me. I will list them by ascending order of time period. My time periods are approximate. (Be aware, I am not a geologist nor paleontologist, just an avid amateur, so take it for what it's worth! )  

 

Cretaceous Formations: Glen Rose, Walnut, Comanche Peak, Edwards , Georgetown,  Buda, and Austin Chalk.

 

 

Glen Rose Formation 106-110 MYA   (Upper and Lower Glen Rose combined here)

 

ECHINOIDS  

Row 1.

 Row 2.

Row 3.

Row 4.

Row 5.

Row 6.

 

1. Hyposalenia  phillipsae              Echinothurid  plates                     Plagiochasma texanum

2,  Goniopygus sp.                           Pygopyrina  hancockensis          Paraorthopsis comalensis   

3.    Loriolia rosana                         Goniopygus  whitneyi                   Pseudodiadema aguilerai           

4.  Polydiadema travisensis           Leptosalenia texana                    Hetearaster texanus                   

5. Coenholectypus sp.                    Pliotoxaster comanchei               Phymosoma texana

6.  Cidarid sp.                                   Heteraster obliquetus                  Paracidarid texanus

 

 

ECHINODERMATA ETC.   

1.

2.

 

1. Unknown Crinoid             Isocrinus annulatus          Echinoderm Madreporite

2. Balanocidarid Spine         Echinoid Spine                  Balanocidarid Spine

 

 

AMMONITES 

 

1. .   Engonoceras  piedernales              Hypacanthoplites mayfieldensis

 

DECAPODS  

1.

 2.

 

1. Crab Claw Unknown          Crab Claw Unknown           Pagurus banderiensis

2. Pagurus banderiensis        Pagurus banderiensis         Pagurus banderiensis

 

ETCETERA  

1.

2.

3.

1.  Porocystis globularis                       Fish Pycnodont Teeth                           Turtle Bone Fragment    

2. Foramnifera Orbitolina (group)      Foramnifera Orbitolina (single)             Coral  Heliopora labyrinthicum

3.     Spirobus Worm          Annelid Worm

 

 

GASTROPODS  

1.

2.

3.

4.

5,

6.

7.

 

 

1. Neritina sp                            Semineritina apparata             Pleutomaria glenrosensis

2. Natica texana                       Nerinia texana                          Nerinia harrisi

3.  Fusus haysensis                 Turbo cuyleri                             Anchura monolifera

4. Cerithium blancoesnsis     Unknown Gastropod               Unknown Gastropod

5. Nerinia incisa                       Pseudomelania pupoides       Tylostoma traviensis

6. Natica traski                          Cerithium bullardi                    Nerinia aquilina

7.. Tylostoma turmidum          Purpuroides harperi                Lunatia praegrandis

 

BIVALVES    

1.

2.

3.

4.

5.

6.

7.

8.

9

10.

 

Other Bivalves : 

11.

12.

13

.

 

BIVALVES

1. Lima wacoensis                         Arca texana                           Ludbrookia arivechensis

2.  Trigonia whitneyi                      Exogyra paupercula              Plicatula parkerae     

3.  Brachidontes pedernalis         Chlamys santoni                   Granocardium pseudopendens   

4.  Neithia occidentalis                Cardium congestum             Arctica comalensis 

5. Pinna comancheana                Granicardium pendens          Fimbria hamiltonae      

6.  Trigonia gordoni                      Homomya comalensis         Laternula simodsi   

7.  Psilomya walker                      Trigonia wendleri                   Homomya knowltoni            

8. Tapes decepta                          Panopea henselli                   Arctica texana      

9.  Psilomya banderiensis           Protocardia texana               Arca medialis     

10. Cyprimeria texana                 Idonearca terminalis             Arctica roemeri

11.  Lopha comalensis                Ceratosterean texanum        Exogyra guadalupae   

12.  Peilinia crenulimargo          Liostrea ragsdalei

13. RUDISTS: Monopleura sp.      Toucasia sp.                  Kimbleia capacis 

 

[JamieLynn]

Walnut Formation  105-106 MYA

ECHINOIDS   

1.

2.

3.

 

1. Leptosalenia  Mexicana            Loriolia rosana                       Heteraster texanus

2. Coenholectypus planatus         Phymosoma texanum           Pliotoxaster sp,  

3.  Tetragramma malbosi             Tetragramma taffi                  Tetragramma malbosi

 

AMMONITES   

       1.     Engonoceras sp                      Engonoceras gibbosum                    Oxytropidoceras sp.

 

ETCETERA 

1.  

  

2

.

1. Unknown Crab Leg                    Unknown Crab Claw                        Unknown Crab Claw

2.                   Parasimilia austinensis                  Foramnifera Dictyconus walnutensis

 

 

GASTROPODS  

1.

2.

3,

1  Neritina sp                           Harpagodes stephensoni                    Monocyphus brittsi

2.  Tylostoma tumidum         Turritella seriatim-granulata                Arrhoges sp.

3.                                             Anchura sp.          Tylostoma travisensis

 

 

BIVALVES 

1.

2.

3.

4.

 

1. Neithia occidentalis           Lima wacoensis                   Neithia sp.

2.  Modiolus sp                       Pholadomya sanctisaba       Neithia texana

3.  Ceratostrean texanum     Texigryphea mucronata       Protocardia texana

4.  Texigryphea roemeri          Cyprimaria texana               Pinna comancheana

 

 

 

[JamieLynn]

Comanche Peak Formation 104-105 MYA

ECHINOIDS  

1.

2.

1. Leptosalenia Mexicana         Coenholectypus  planatus        Heteraster texanus

2.  Phymosoma texanum          Tetragramma sp

 

AMMONITES     

1.  Engonoceras gibbosum              Engonoceras sp               Oxytopidoceras sp

 

GASTROPODS   From smallest (1/4 inch) to largest (2 inches)

1.

2..

1. Nerita sp                   Tylostoma elvatum        Turitella sp

2.  Nerinia sp.            Arrhoges sp                      Unknown Gastropod

 

BIVALVES  From smallest (1/2 inch) to largest (4 inches)

1.

2.

3.

 

1. Lima wacoensis             Ludbrookia  arivechensis            Neithia subalpina

2.   Tapes decepta             Laternula sp.                                  Homomya sp

3.  Panopea regularis        Ceratostrean  texanum                 Pinna comancheana

 

OTHER

1. Coral Parasimilia austinensis

[JamieLynn]

Edwards Formation  103-104 MYA

 

RUDISTS 

1.

2.

 

            1. Eoradiolites sp                           Toucasia patagiata                           Caprinuloidea ? crassifibra

           2. Monopleura sp.                          Caprinuloidea gracilis                        Toucasia texana

 

GASTROPODS 

          1. Ceritella proctori                                    Nerinia kervillensis                                Nerinia cultrispira

 

BIVALVES

                       1. Chondrodonta munsoni                                  Neithia duplicicosta

[JamieLynn]

Georgetown Formation    100-102 MYA

 

ECHINOIDS  

  1. Echinoid Spine                             Holaster simplex                         Macraster elegens

 

AMMONITES  

 

              1. Mariella sp                             Cymatoceras hilli                         Mortoniceras sp

 

 

GASTROPODS   

                   

                 1.Turritella sp                          Leptomaria macilenta                        Turitella irrorata

 

BIVALVES   

1.

2.

3.

4. 

 

1. Plicatula  subgurgitis                Unknown Bivalve               Neithia wright

2. Illymatogyra arietina                  Rastellum carinatum        Neithia theodori

3.  Neithia georgetownensis          Trigonia clavigera             Neithia altana

4. Lopha subovata                        Rudist Monopleura sp.       Brachiopod Waconella (Kingena) wacoensis      

 

[JamieLynn]

Buda Formation    98-100 MYA

 

AMMONITES  

1.

      1.. Faraudiella archerae                      Cymatoceras hilli                           Budaiceras hyatti

 

GASTROPOD AND BIVALVES  

1

.

2.

 

1. Turritella sp                Illymatogyra ariatina         Neithia texana 

2. Neithia budensis       Rastellum carinatum       Texigryphea roemeri

 

[JamieLynn]

Austin Chalk Formation   85-89 MYA

 

AMMONITES   All are approx. 4 inches

   1.  Eutrophoceras campbelli               Pachydiscus travisi              Unknown Ammonite

 

ETCETERA   

    1. Unknown (possibly crinoid)                Unknown Coral                            Ammonite Baculite sp. 

 

 

GASTROPODS   Both approx. 2 inches

 1,.  Anchura texana          Unknown Gastropod

 

BIVALVES

1.

2.

3.

4.

5

.

 

 

1. Unknown Bivalve             Trigonia thoracica                   LIma wacoensis quadranglaris

2. Neithia austeninsis          Astarte liniolata                        Exogyra tigrena

3. Pycnodont aucella           Inoceramus subquadratus      Exogyra laeviscula

4. Ostrea centrensis             Lopha panda                             Inoceramos mytilopsis

5. Exogyra ponderosa erraticostata     Exogyra ponderosa

 

[Scylla]

Wow, that's a great collection and useful guide to ID's. Thanks!

[grandpa]

Excellent collection, cataloguing and quality photos.  I'll be using this for my own collection.  Great work.

[JamieLynn]

Thanks y'all!  I probably made a few mistakes, but hey, you get what you pay for.....hahhaahh

[Tidgy's Dad]

Brilliant. 

And very, very useful. 

[erose]

Wow. That is a lot to take in.  Cool project. Vast majority looks spot on. I think the Neitheas need sorting out. N. subalpina should not be in the Comanche Peak and N. occidentalis is not a likely Buda species. But that is probably open to interpretation and it may take much closer inspection to get positive IDs. 

 

The only other thing that jumped out is the Pliotoxaster inflatus in the Walnut.  There is definitely a Pliotoxaster in the Keys Valley Member but what species I am not sure.  They look a lot like P. inflatus from the Goodland but maybe not exactly like them.

 

Don't hesitate to just use the Genus if you are not sure.  In my collection those Walnut Pliotoxaster are labeled as "Pliotoxaster sp." and I am currently quite happy with just that.  Everyone gets hung up on nailing that species but it isn't always possible or even necessary

 

Oh and the only other suggestion would be the need for some sort of scale.  For example the Lunatia looks the same size as the Neritina.  And it sure as heck isn't.

[erose]

PS Walk thru all the spellings again. It's Pholadomya sanctisabae not Phylodoma.  That was the only one I caught but check all the others.  And I KNOW how hard it is to proof your own work. Just about impossible.  I found I have to step away for some period of time and then print it out and read fresh to catch mistakes.  But all easy to fix.

[JamieLynn]

Thanks @erose for your input!  I will work on all those suggestions! Plus, I just found a few new fossil from the Edwards today that I will be adding. 

[FossilNerd]

WOW! What a great visual guide to things found in your local formations. I'm sure putting this together was not a quick task. Thanks for sharing! 

[JamieLynn]

Thanks @FossilNerd ! As you can see...I am a bit of a nerd about fossils too! 

 

[Leslie from Austin]

I'm so glad I found this! You've created an invaluable resource that I'll refer to quite a bit-thanks!

[JamieLynn]

Thanks @Leslie from Austin! I will be adding to it so do check back! You can also check out my website which does have the same stuff. www.fossil-quest.com 

[JamieLynn]

Okay! Some updating! I think I got all the Measurements up.  Will be adding a few new fossils next....I keep finding stuff! 

[Even]

Brilliant! 

[LanceH]

Great collection.

 

Yeah, there was a reason I went with NorthTexasFossils.  I knew there were geologic, faunal and preservational differences further south.  Also I don't get to hunt that far away so I have no specimens from there. 

[Jared C]

@JamieLynn, Have you ever considered getting your Paracidarid texanus prepped? I highly suspect the aristotle's lantern may be present on it. Mine had a very similar looking, roughly pyramid shaped "hump" that capped the mouthparts

[JamieLynn]

6 hours ago, Jared C said:

@JamieLynn, Have you ever considered getting your Paracidarid texanus prepped? I highly suspect the aristotle's lantern may be present on it. Mine had a very similar looking, roughly pyramid shaped "hump" that capped the mouthparts

 But I think that is the top, not the bottom. 

[Jared C]

1 hour ago, JamieLynn said:

 But I think that is the top, not the bottom. 

rookie mistake