Showing posts with label Utah. Show all posts
Showing posts with label Utah. Show all posts

Sunday, March 15, 2020

Salix sp. leaf from the Green River formation

This long, narrow leaf is most likely from a member of the Willow family, Salix sp. and comes from the Parachute Creek member of the Green River formation (Eocene, Lutetian stage).  It was found in Bonanza, Utah and I purchased it because it came with an ID. I am hoping that I can use this and other identified specimens that I purchase to help ID fossils that I have found in the field. There are not many resources easily accessible that show pictures and names for plant and insect fossils from the Green River formation.  I know I have found other examples of Salix sp. that are larger and more recognizable than this specimen but I need to go through my findings and locate it.



Friday, March 13, 2020

Cardiospermum coloradensis leaf from the Green River formation

Soapberry plants are typically found in the tropics and their presence in a northerly latitude like where NE Utah is indicates that the climate used to be much warmer than it is now. Below is a leaf from the Soapberry family,  called Cardiospermum coloradensis, that is also called "Balloon Vine".   Fossils of these leaves are somewhat common in the Parachute Creek member of the Green River formation (Eocene, Lutetian stage), but most of what I have found are smaller. I purchased this piece because of the good preservation and size of the leaf.  I identified it based on this image from James St. John's Flickr page.




Wednesday, March 11, 2020

Caesalpinites sp. leaf from the Green River formation

Here is another fossil leaf from the Parachute Creek member of the Green River formation (Eocene, Lutetian stage) that I purchased because it came with an ID. It's a leaf called Caesalpinites sp.  The fossil is small and somewhat faint against the rock but you can make out the central vein and overall shape of the leaf.  This specimen comes from a site near Bonanza, Utah.  I'm having a hard time finding any more info about this genus to try and narrow down the species. I've seen other leaves labelled as Caesalpinites falcata from the same area but they look different than my specimen. It could be a different species or maybe the plant had different shaped leaves on different areas. 



Saturday, February 22, 2020

Bathyuriscus fimbriatus trilobite from the Marjum formation

Here is an uncommon trilobite from the Marjum formation of Utah, Bathyuriscus fimbriatus. This comes from the same area as the millions of Elrathia kingii fossils that are ubiquitous at fossil show, but from a slightly younger layer. You can tell this species apart from E. kingii by the larger pygidium and the thorax segments that extend just a little father than the margin of the pygidium. This specimen is missing the free checks, or librigena .



There is a good picture of a complete specimen of Bathyuriscus fimbriatus that can be seen on the Western Trilobite Association webpage.

The Marjum formation is middle Cambrian in age, Drumian stage (503 mya).

Wednesday, February 3, 2016

Spiriferellina ? or Punctospirifer? brachiopod from the Chainman formation of Utah

Here is another mystery brachiopod from the Chainman formation of Utah. It is a triangular shaped shell which is longer than wide. Both valves have coarse folds that extend from the hinge line to the anterior margins with a simple fold and sulcus. The hinge line is flat and runs the length of the anterior margin. A small triangular shaped delthyrium is present on the anterior of the pedicle valve but it is only 1/2 the length of the hinge line. My initial speculation as to the identity of this shell was that it is a Punctospirifer sp. But while reading through some publications concerning Mississippian faunas in Western US formations, I came across a similar looking shell called Spiriferellina sp. I want to lean towards the latter name because it would be more appropriate for the region I found it in.  Still, without a complete shell or multiple examples I probably can not truly identify this specimen.

Brachial valve
Anterior
Pedicle valve
Posterior
Profile

This specimen came from the Chainman formation at Conger Springs (west of Delta), Utah and is Carboniferous (Mississippian epoch, Visean stage of the ICS or Mississippian period, Chesterian stage in the US) in age.

Sunday, January 31, 2016

Reticulariina sp. ? brachiopod from the Chainman formation of Utah

I believe this next fossil is a Reticulariina sp. brachiopod but am not sure of the species. It comes from the Chainman formation of Utah which is lower Carboniferous in age (Mississippian epoch, Visean stage of the ICS or Mississippian period, Chesterian stage in the US). The shell is small, with a very convex pedicle valve and a flat to slightly convex brachial valve. It sort of resembles a Cyrtia sp. type brachiopod that occurred in the Devonian. Each valve has very coarse plications with 2-3 on each side of the median. There is a sulcus and fold structure present on the valves but it is only noticeable at the anterior margins. It is hard to see but it appears there are some sort of concentric growth lines decorating the shell surface as well. The posterior of the pedicle valve has a large triangular interarea under a beak that recurves back.

Brachial valve
Anterior
Pedicle valve
Posterior
Profile


This specimen came from the Chainman formation at Conger Springs (west of Delta), Utah and is Carboniferous (Mississippian epoch, Visean stage of the ICS or Mississippian period, Chesterian stage in the US) in age.

Thursday, January 28, 2016

Anthracospirifer sp. brachiopod from the Chainman formation of Utah

I believe this next brachiopod fossil is Anthracospirifer sp.. It comes from the Chainman formation at Conger Springs in Utah. The shell is missing part of a "wing" but enough is left to help identify it. The pedicle and brachial valves are equally convex, rectangular shaped and have coarse plications. A sulcus on the pedicle valve corresponds with a single fold on the brachial valve. The pedicle valve has a wide interarea with a recurved beak.

Brachial valve
Anterior
Pedicle valve
Posterior
Profile


There are a number of known species of Anthracospirifer but little literature on what specific forms occur in the Chainman formation. One resource, "Mississippian Stratigraphy of the Diamond Peak Area, Eureka County, Nevada", Brew, David, 1971, Indicates that A. occiduus, A. pellaensis, A. increbescens and A. bifurcatus are found in equivalent strata in Nevada but I can find no clear illustrations of those species or those I find do not match what I have here..

The reference "Brachiopoda of the Amsden Formation (Mississippian and Pennsylvanian) of Wyoming.", MacKenzie Gordon, Jr., 1975 lists multiple species of Anthracospirifer, including A. occiduus but none seem to match my specimen.

This specimen came from the Chainman formation at Conger Springs (west of Delta), Utah and is Carboniferous (Mississippian epoch, Visean stage of the ICS or Mississippian period, Chesterian stage in the US) in age.

Monday, January 25, 2016

Cleiothyridina hirsuta brachiopod from the Chainman formation of Utah

Looking very much like an Athyris sp. brachiopod, this fossil is Cleiothyridina hirsuta.  It is a rounded to subovate shell with both the pedicle and brachial valve equally convex. The surface of each valve has concentric growth lines but no obvious costae or sulcus.

Brachial valve
Anterior
Pecidle valve
Posterior
Profile

I used the reference "Brachiopoda of the Amsden Formation (Mississippian and Pennsylvanian) of Wyoming.", MacKenzie Gordon, Jr., 1975 pg. 56, plate 7, fig 31, 38-40, 42-45, 58, 59 to identify this brachiopod. This specimen came from the Chainman formation at Conger Springs (west of Delta), Utah and is Carboniferous (Mississippian epoch, Visean stage of the ICS or Mississippian period, Chesterian stage in the US) in age.

Friday, January 22, 2016

Inflatia sp. brachiopod from the Chainman formation of Utah

I found this specimen of a spiny productid brachiopod at Conger Springs, Utah. I believe it is an example of the genus Inflatia. I am unsure as to the species because the preservation is not the best. It was a spiny brachiopod but not as spiny as a similar genus, Juresania.  The pedicle valve is very convex while the brachial valve is flat to slightly convex and the margins of both meet at a 90 degree angle to the brachial valve.  Both valves are decorated with linear costae but only the pedicle valve has spines. The spines appear somewhat randomly placed although there could be a pattern that I don't recognize.

Pedicle valve
Anterior
Brachial valve
Posterior
Profile

I used the reference "Brachiopoda of the Amsden Formation (Mississippian and Pennsylvanian) of Wyoming.", MacKenzie Gordon, Jr., 1975 pg. 36, plate 3, fig 1-9 to identify this brachiopod.
This specimen came from the Chainman formation at Conger Springs (west of Delta), Utah and is Carboniferous (Mississippian epoch, Visean stage of the ICS or Mississippian period, Chesterian stage in the US) in age.

Tuesday, January 19, 2016

Crurithyris sp.? brachiopod from the Chainman formation of Utah

This next brachiopod looks very similar to a genera called Crurithyris that is present in the Pennsylvanian. I can't locate any literature or examples from the Chainman formation at Conger Springs, Utah that indicate this could be any other genera. So I am tentatively labeling this as Crurithyris sp. The shell is small, wider than long with a very convex pedicle valve and a slightly convex brachial valve. The valves are smooth with no obvious ornamentation. The pedicle valve recurves back over the interarea and the margins of the valves are flat with no evidence of a fold or sulcus.

Brachial valve
Anterior
Pedicle valve
Posterior
Profile

This specimen came from the Chainman formation at Conger Springs (west of Delta), Utah and is Carboniferous (Mississippian epoch, Visean stage of the ICS or Mississippian period, Chesterian stage in the US) in age.

Saturday, January 16, 2016

Eumetria costata brachiopod from the Chainman formation of Utah

While search for fossils at Conger Springs, Utah I found lots of examples of these little brachiopods called Eumetria costata. They are small shells that are longer than wide with the widest point about midway between the umbo and the anterior margins. Each valve is roughly equally convex and has around 20 radiating costae on the surface. The umbo extends beyond the brachial valve and curves slightly to the point where the circular formen opening is located.

Specimen #1 - Brachial valve
Anterior
Pedicle valve
Posterior
Profile

Specimen #2 -Brachial valve
 Anterior
 Pedicle valve
 Posterior
 Profile


I used the reference "Geology of Millard County, Utah", Lehi F. Hintze & Fitzhugh D. Davis, 2003 pg. 106, fig.142 to identify these brachiopods. These specimens came from the Chainman formation at Conger Springs (west of Delta), Utah and are Carboniferous (Mississippian epoch, Visean stage of the ICS or Mississippian period, Chesterian stage in the US) in age.

Wednesday, January 13, 2016

Composita elongata brachiopod from the Chainman formation of Utah

Another Composita species that I found in the Chainman formation of Utah is Composita elongata. This species is narrower than some but this particular specimen has a very strong fold and sulcus that is well developed. According to MacKenzie (see below for reference), C. elongata may intergrade with C. subtilita (see previous post). This means that the two species sometimes share the same form but remain distinct.

I used the reference "Brachiopoda of the Amsden Formation (Mississippian and Pennsylvanian) of Wyoming.", MacKenzie Gordon, Jr., 1975 pg. 64, plate 10, fig 16-25 to identify this brachiopod.This specimen came from Conger Springs west of Delta, Utah and is Carboniferous (Mississippian epoch, Visean stage of the ICS or Mississippian period, Chesterian stage in the US) in age.

Pedicle valve
Anterior
Brachial valve
Posterior
Profile (with pedicle valve on top)
Profile (with brachial valve on top)

I used the reference "Brachiopoda of the Amsden Formation (Mississippian and Pennsylvanian) of Wyoming.", MacKenzie Gordon, Jr., 1975 pg. 64, plate 10, fig 16-25 to identify this brachiopod.