Show Us Your Fossils Challenge Mode: Ordered By Geologic Time Period!

[Ludwigia]

And a Myophorella hudlestoni bivalve from the Late Jurassic Oxfordian at Kalkriese in Lower Saxony, Germany.

 

[Mikrogeophagus]

Here's something from the Lower Cretaceous. A Hemiaster whitei echinoid with Plicatula oysters and tube worms encrusted on it from the Goodland Formation of North Central TX.

 

Edited September 9, 2022 by EPIKLULSXDDDDD

[JohnJ]

19 minutes ago, EPIKLULSXDDDDD said:

A Holaster whitei echinoid....

 

Holasters are domed shaped with a flat ventral side.  This is likely a Hemiaster whitei Clark.   

[GPayton]

10 minutes ago, JohnJ said:

 

Holasters are domed shaped with a flat ventral side.  This is likely a Hemiaster whitei Clark.   

Is there a difference between Hemiaster and Heteraster? Or is one just an old genus name for these Texas urchins that has now been replaced by the other? 

[Mikrogeophagus]

23 minutes ago, JohnJ said:

 

Holasters are domed shaped with a flat ventral side.  This is likely a Hemiaster whitei Clark.   

Nice catch. Guess I got my H's mixed up 

[JohnJ]

8 minutes ago, GPayton said:

Is there a difference between Hemiaster and Heteraster? Or is one just an old genus name for these Texas urchins that has now been replaced by the other? 

Two separate and valid genera with distinct characteristics.  

 

https://www.nhm.ac.uk/our-science/data/echinoid-directory/taxa/search.jsp?begins=H

[Mikrogeophagus]

14 minutes ago, GPayton said:

Is there a difference between Hemiaster and Heteraster? Or is one just an old genus name for these Texas urchins that has now been replaced by the other? 

I've seen the genus Enallaster used in some older stuff that is also called Heteraster. Perhaps that is the old name?

[FranzBernhard]

One of those conglomerate fossils from the upper Cretaceous Kainach Gosau, collected about a week ago, incl. field pics. Freshly discovered while prying around a little bit with a screwdriver in that fossiliferous conglomerate bed, could not resist recovering it, because snail is so nicely perched on matrix. A small hammer and two screwdrivers were needed for recovery in this case . Specimen was recovered complete as pictured, no reassembly needed, but a few cracks stabilized with superglue. Yes, my taste is a little bit - rough or coarse ? I like it very much!

Franz Bernhard

[Ludwigia]

Amaea (Confusiscala) maxima from the Paleocene at the Kroisbachgraben in Salzburgerland, Austria.

 

[GPayton]

A shark tooth, possibly Odontaspis, from the Eocene Reklaw Formation in east Texas. The Piney Woods in the eastern half of the state are a notoriously difficult area to find much fossil material in besides petrified wood. That, combined with the fact that this was my first time ever using my homemade PVC pipe and chicken wire sifter screen, made this a very special find. 

 

Edited September 9, 2022 by GPayton

[rocket]

middle Eocene, Messel Pit, Germany, a nice mammal, Kopidodon, size around 80 cm from snout to tail

[PR0GRAM]

1 hour ago, rocket said:

middle Eocene, Messel Pit, Germany, a nice mammal, Kopidodon, size around 80 cm from snout to tail

Holy S@&$! That’s freaking amazing, what a beautiful piece!

[siteseer]

Hyaenodonts were carnivorous mammals that are not directly related to forms we know as carnivores, or more correctly, carnivorans (dogs, cats, bears, hyenas, weasels, raccoons).   "Hyaenodont" is an informal term for "hyaenodontid" which refers to the extinct family, Hyaenodontidae.  This group appeared early in the Eocene and were successful predators in North America and Europe across the Eocene and Oligocene.  They would die out in North America by the end of the Oligocene but survived into the Miocene in Africa.

 

The genus, Hyaenodon, ranged in size from that of a housecat to that of a lion and it had a large head relative to its body.  This jaw section measures 2 1/4 inches (58mm) across. 

 

Hyaenodon sp.

Early Oligocene

Brule Formation

north of Chadron, Dawes County, Nebraska

[siteseer]

Astrodapsis sp.

Late Miocene

Branch Canyon Formation

New Cuyama, Santa Barbara County, California

 

This is an example of an echinoid that ended up on the back of a larger one with the larger one being cracked with a clump of hard matrix stuck to it.  The little one is in great shape and measures roughly 1 1/4 inches in maximum diameter (32mm).

 

I've seen some, larger matrix pieces that eroded nicely and needed minimal prep but the rock doesn't chip cleanly so it takes a lot of work to make a piece look nice if it isn't already mostly ready for display.  I heard the land changed hands in the past 20-25 years and someone built on it and put up a fence.  I used to see specimens from there at shows.

[siteseer]

This is a petrosal (used to be called a periotic), an inner ear bone, of a dolphin - probably a modern genus.  It comes from the Early Pliocene of Peru which is a time when the last of the primitive whale groups of the Oligocene and Miocene were disappearing and when many modern genera were appearing.  Whale specialists hope to find a skull with the periotics still in place because they are distinctive but they also usually fall out of the skull before final burial and roll away in a current.  This one measures about an inch (26mm) across. 

 

unidentified dolphin

Early Pliocene

Pisco Formation

Sacaco, Peru

 

 

[Ludwigia]

Echinometra sp. from the Pleistocene at Hurghada, Egypt.

 

[rocket]

fossil dog skull, late pleistocene, Rhine River, SW-Germany

[PR0GRAM]

Okay, sorry for the wait let’s get this ball rolling again again! If we get stuck in the Ediacaran again just tag me I have a few more macro fossils to share.

 

Microbial Mat Texture

Long Mynd, Shropshire, U.K.

Photographed with dramatic lighting.

 

 

[Ludwigia]

Agraulos ceticephalus from the Middle Cambrian in Skryje-Buchna, Czech Republic.

 

[Ludwigia]

Ogyginus corndensis from the Middle Ordovician Darwillian at Llandrindod Wells, Wales.

 

[Paleorunner]

From the Silurian, this partial Eurypterus tetragonopthalmus. Podilskyi area - Ukraine.

 

 

[Ludwigia]

The Conodont Polygnathus foliatus from the Middle Devonian North Evans Limestone at Penn Dixie, NY.

 

[siteseer]

Here's a blastoid to cover the Mississippian.  It looks like it has a piece of crinoid on it or is it its own stem?  What is that?

 

Blastoids are a group of extinct echinoderms that appeared during the Ordovician and survived all the way to the end of the Permian.

 

Pentremites sp.

Late Mississippian

Glen Dean Formation

Crawford County, Indiana

3/4 of an inch (18mm) long

 

 

 

[siteseer]

For the Late Carboniferous (Pennsylvanian), I have this large chondrichthyan tooth, Ctenacanthus occidentalis.  Ctenacanths have been said to be the ancestral group for all modern sharks.  Ctenacanths were one of the few cartilaginous fish groups that survived the end-Permian mass extinction.

 

This specimen shows a lot of wear.  It may be evidence of much slower tooth replacement in ancient forms compared to modern sharks.

 

Ctenacanthus occidentalis

Late Carboniferous

Scholkowo, Moscow area, Russia

just over 1 1/2 inches (39mm) across the base of the root

[siteseer]

The Permian can be a sticking point so I'll pop in these brachiopods.

 

Hustedia mormoni

Early Permian

Pueblo Formation

Brown County, Texas