March 2017 Finds Of The Month

[piranha]

12 minutes ago, ynot said:

Just curious, but after all of the above, how would You label it?

 

 

The same way I suggested labeling it before there was any "all of the above". 

 

Indeterminate ptychopariid.

 

 

[ynot]

4 minutes ago, piranha said:

 

 

The same way I suggested labeling it before there was any "all of the above". 

 

Indeterminate ptychopariid.

 

 

"slaps forehead" Oh duh

 

Thanks Sir.

Tony

[EMP]

8 hours ago, piranha said:

Known from one fairly complete example and several fragments.

 

Known from *two* fairly complete examples .

[piranha]

14 minutes ago, EMP said:

Known from *two* fairly complete examples .

 

 

Surely there are many others since Rasetti's paper in 1961 and your find in 2017.  Reinhardt 1974 also mentions finding indeterminate trilobites without elaborating on the details.  It is difficult to quantify the actual totals without having access to collection data at institutions that have Frederick Formation trilobites.  

 

 

[EMP]

8 hours ago, piranha said:

Surely there are many others since Rasetti's paper in 1961 and your find in 2017.  Reinhardt 1974 also mentions finding indeterminate trilobites without elaborating on the details.  It is difficult to quantify the actual totals without having access to collection data at institutions that have Frederick Formation trilobites.  

 

I doubt it. The area has been built up a lot since the 1960s, and many of the past localities are now homes or shopping centers. Even some of the quarries have closed.

[piranha]

12 hours ago, piranha said:

...It is difficult to quantify the actual totals without having access to collection data at institutions that have Frederick Formation trilobites.  

 

4 hours ago, EMP said:

I doubt it. The area has been built up a lot since the 1960s, and many of the past localities are now homes or shopping centers. Even some of the quarries have closed.

 

 

There may not be many trilobites to collect now, but they are well represented and documented in institutional collections.

Because they have little scientific value, indeterminate partial trilobites are not recorded with a great amount of specificity.

 

 

Rasetti 1961:

 

 "As there is a variety of cranidia, most of which are poorly known or unknown elsewhere, there is little ground on which to base tentative references of cranidia and pygidia to the same species.  Trilobite fragments from the Dunderbergia zone, especially the beds at locality ccm/4, indicate the presence of other species in addition to those described herein, too poorly represented to warrant illustration."

 

 

Reinhardt 1974: Adamstown Member trilobites - "Locally abundant, poorly silicified trilobites."

 

Also, Brezinski 2004 published some figures of unidentified Frederick Formation trilobites.

 

Rasetti, F. (1961)
Dresbachian and Franconian trilobites of the Conococheague and Frederick Limestones of the Central Appalachians.  
Journal of Paleontology, 35(1):104-124 

 

Reinhardt, J. (1974)
Stratigraphy, sedimentology, and Cambro-Ordovician paleogeography of the Frederick Valley, Maryland.
Maryland Geological Survey, Report of Investigations, 23:1-73

 

Brezinski, D.K. (2004)
Stratigraphy of the Frederick Valley and its relationship to Karst Development.
Maryland Geological Survey, Report of Investigations, 75:1-101

 

[TNCollector]

I will also try my hand at the invertebrates!

 

This is a lovely conulariid that I found earlier this month. I just got done prepping him out of his phosphatic cocoon (nodule) that he has been brewing in for 340 million years. It is by far the largest conulariid I have ever found or seen in person. This site has many conulariids, but they are usually a centimeter or less in length. Unfortunately this specimen is not complete, but in life, he would have been really long!

 

What also makes this specimen special is that the 3-dimensional rectangular structure was preserved, which is what it would have been like when it was alive. Other than that they appear to be a type of cnidaria, very little is understood about these creatures.

 

Conularia sp.

Early Mississippian Period (Early Carboniferous)

East Kentucky, USA

White square is approximately 1 cm^2

[piranha]

I have been working overtime to come up with some more info on the mystery trilobite.  After a lot of cross-referencing of Quebecaspis faunas of similar age, I finally discovered the undetermined cranidium no. 4 from Rasetti 1961 has been assigned by Eoff 2002, to Tholifrons minutus Palmer, 1968.  By process of elimination, Rasetti's undetermined cranidium no. 4 is the best match with the mystery trilobite.  Tholifrons minutus figures 29-43 are attached for comparison.  

 

 

 

figures from:

 

Eoff, J.D. (2002)
Late Cambrian (Steptoean) trilobites from the Cow Head Group, western Newfoundland.
M.S. Thesis, University of Oklahoma, 250 pp.

 

Tholifrons minutus Palmer, 1968 - Plate 24, Figures 29-43

The undetermined cranidium no. 4 in Rasetti (1961, p. 120-121, pl. 24, fig. 27) represents T. minutus because its glabella is relatively long (sag), and its palpebral furrows appear to be directed obliquely inward, although it appears to have longer (trans) posterior fixigenae.

 

[EMP]

2 hours ago, piranha said:

I have been working overtime to come up with some more info on the mystery trilobite.  After a lot of cross-referencing of Quebecaspis faunas of similar age, I finally discovered the undetermined cranidium no. 4 from Rasetti 1961 has been assigned by Eoff 2002, to Tholifrons minutus Palmer, 1968.  By process of elimination, Rasetti's undetermined cranidium no. 4 is the best match with the mystery trilobite.  Tholifrons minutus figures 29-43 are attached for comparison.

 

 Thank you so much Piranha! This means a lot to me!

 

I've never heard of that genus or species before, that must have really been a lot of digging.  

[piranha]

6 minutes ago, EMP said:

 Thank you so much Piranha! This means a lot to me!

I've never heard of that genus or species before, that must have really been a lot of digging.  

 

 

It was like trying to find a genal spine in a haystack!  

 

[Malcolmt]

Very nice conularid, I always pick them up when I see them, unfortunately that is only probably a half dozen a year. Either not that common or not that well preserved in the Ordovician that I hunt. Based on how fragile the fossils usually are I suspect the later.

[Welsh Wizard]

A recent find picked up on 19th March 2017 and prepped this week.

 

The find is a combination of two classic prehistoric marine reptile fossils.

 

Firstly a one and a half inch black plesiosaur tooth, and secondly a paddle digit from a large ichthyosaur.

 

The fossil was found in two pieces and it was only when I got home did I realise they fitted together.

 

Late Triassic

Rhaetian

Aust Cliff Bone Blue Anchor Bed

Westbury Formation

Gloucester

United Kingdom

[Welsh Wizard]

[Welsh Wizard]

[Welsh Wizard]

[RCFossils]

Here is my submission for VFOM.

An extremely rare legless amphibian from the Mazon Creek Deposit.

Phlegethontia longissima Fritsch,1875

Carbondale Formation

Francis Creek Shale (approx 307 MYA)

Collected at Pit 11 March 1st 2017

Concretion split open March 21st 2017

 

[RCFossils]

Phlegethontia

[RCFossils]

Here is my submission for IFOM

A rare Thylacocephala from the Mazon Creek deposit.

The species is Convexicaris mazonensis Schram 1990

Carbondale Formation

Francis Creek Shale (approx 307 MYA)

Collected at Pit 11 March 1st 2017

Concretion split open March 19th 2017

This is one of the best preserved examples ever collected

[BobWill]

I know...it's only a clam, and it's only one valve. It's not even complete, but the size of this bivalve of the pen shell family makes it a keeper. I thought y'all would like to see it even if it doesn't get many votes.

 

I found it in the Finis Shale Member of the Graham Formation at Jacksboro Texas. That's the Virgil Series, Cisco Group of the Late Pennsylvanian Period.

 

The smaller ones we find there have been identified as Aviculopinna (= Pteronites) percuata Meek 1864 so I assume this is just a Texas-sized version of the same species. The whole thing is 20 inches long (51cm). It was found in the limestone at the top of the shale bank of the Lost Creek Dam borrow area. It broke at 2 places as I was getting it out. Luckily one of the breaks exposed the part at the large end that broke away before preservation. Oherwise I might have destroyed that part when I trimmed it to size.

 

I first saw it in a large rock, too big to carry out, on the 26^th of November, 2016 and started chiseling a trench down both sides. I worked on it on the next three trips to Jacksboro. The first picture is from the 31^st of December when I returned to continue chiseling the trenches down both sides. On the next trip on the 11^th of February half of it broke off in a small enough piece to carry out and begin prep. I finished the prep on the first half on the 6^th of March. On Saturday the 25^th of March, 2017 I went back for the rest. It was a Dallas Paleontological Society field trip so I knew I would have some help getting it down the bank and into a wheelbarrow. The second picture shows the two halves before I started removing excess matrix and preping the second half. Yesterday on the 27^th I finished all of the prep I will attempt with my hand tools.^.

 

 

[JarrodB]

23 hours ago, BobWill said:

I know...it's only a clam, and it's only one valve. It's not even complete, but the size of this bivalve of the pen shell family makes it a keeper. I thought y'all would like to see it even if it doesn't get many votes.

 

I found it in the Finis Shale Member of the Graham Formation at Jacksboro Texas. That's the Virgil Series, Cisco Group of the Late Pennsylvanian Period.

 

The smaller ones we find there have been identified as Aviculopinna (= Pteronites) percuata Meek 1864 so I assume this is just a Texas-sized version of the same species. The whole thing is 20 inches long (51cm). It was found in the limestone at the top of the shale bank of the Lost Creek Dam borrow area. It broke at 2 places as I was getting it out. Luckily one of the breaks exposed the part at the large end that broke away before preservation. Oherwise I might have destroyed that part when I trimmed it to size.

 

I first saw it in a large rock, too big to carry out, on the 26^th of November, 2016 and started chiseling a trench down both sides. I worked on it on the next three trips to Jacksboro. The first picture is from the 31^st of December when I returned to continue chiseling the trenches down both sides. On the next trip on the 11^th of February half of it broke off in a small enough piece to carry out and begin prep. I finished the prep on the first half on the 6^th of March. On Saturday the 25^th of March, 2017 I went back for the rest. It was a Dallas Paleontological Society field trip so I knew I would have some help getting it down the bank and into a wheelbarrow. The second picture shows the two halves before I started removing excess matrix and preping the second half. Yesterday on the 27^th I finished all of the prep I will attempt with my hand tools.^.

 

 

Very cool. 

[ArrowHead]

I'm still new to TFF but I have two specimens that I'm willing to throw in the hat for consideration. Nice thing about being a newbie is you nothing to loose and no reputation to spoil.

 

The first specimen was recovered from the Round Mountain Formation at the Ernst Quarries near Sharktooth Hill on 3/26/17. This is a lower tooth from C. hastalis (tactfully avoiding the Cosmoplitodus/Charchardon genus controversy). This species is not uncommon in the deposit but what makes this tooth special is its size and quality. It is 3.25" in length, placing it at or near maximum size, with great color and in absolute perfect condition. I had posted this tooth in the general discussion earlier this week to get member's opinion whether to leave this tooth in the matrix. The unanimous response was to leave it in the matrix so the matrix is where it will remain. I sure would love to see the lingual side though .....maybe someday.

 

 

[ArrowHead]

The second specimen also recovered from the Round Mountain Formation at the Ernst Quarries near Sharktooth Hill, a day earlier on 3/25/17. I believe this tooth is from the pygmy sperm whale Aulophyseter morricei however it is more curved that I typically see for this toothed whale. There are a number of toothed whales recorded at this middle Miocene deposit so my best id could be debatable. Please advise if you have other opinions on the identification.  I have found it very difficult to recover intact examples of this fragile whale tooth and I am very pleased to finally have a complete one. I have some minor repair work to do but it will be easy to endure. Yes, I had a couple very good days in the dirt!

[Kane]

The bar on this month is certainly quite high 

[EMP]

Where do we vote?

[ynot]

4 hours ago, EMP said:

Where do we vote?

A poll will be set up tomorrow for vert and another for invert.