Jump to content

My trilobite of the week.


rew

Recommended Posts

I can't resist adding this one extra super bonus trilobite, the rare and much larger (and cuddlier) subspecies Greenops boothi plushtoyi.  This is only found in a thin layer in Ithaca, New York.

Greenop_boothi_plushtoy.jpg

  • I found this Informative 4
  • Enjoyed 2
Link to comment
Share on other sites

That is awesome.... a well known member of the Fossil Forum that I helped out a few years ago gave my grand daughter one of these and it is still one of her favorites. Because of this Trilobite was one of her first 50 words...... She is now sharing it with her new baby sister.........

  • I found this Informative 1
  • Enjoyed 1
Link to comment
Share on other sites

11 hours ago, rew said:

This midweek bonus trilobite (#24) is a more common cousin of Bellacartwrightia, Greenops boothi, from the Moscow Shale of Erie County, New York.  It is middle Devonian in age.  This specimen, 27 mm long, is typical size for the species.  It shares its rock with a piece of horn coral, a reminder that back in the Devonian upstate New York was a shallow tropical sea, south of the equator.

dorsal-small.jpg   whole-plate-small.jpg

This trilobite is a Greenops barberi, not a Greenops boothi

  • I found this Informative 2
Link to comment
Share on other sites

11 hours ago, rew said:

I can't resist adding this one extra super bonus trilobite, the rare and much larger (and cuddlier) subspecies Greenops boothi plushtoyi.  This is only found in a thin layer in Ithaca, New York.

Greenop_boothi_plushtoy.jpg

 

That's not true, we also have them at Penn Dixie. $15 a piece, they're found in the Gift Shop member of the Windom, lol.

  • I found this Informative 1

Jay A. Wollin

Lead Fossil Educator - Penn Dixie Fossil Park and Nature Reserve

Hamburg, New York, USA

Link to comment
Share on other sites

3 hours ago, GerryK said:

This trilobite is a Greenops barberi, not a Greenops boothi

 

The difference between those two species appears to be primarily in the length of the pygidal lappets, with G. boothi having them longer.  It isn't clear to me where my specimen lies.

Link to comment
Share on other sites

7 hours ago, DevonianDigger said:

 

That's not true, we also have them at Penn Dixie. $15 a piece, they're found in the Gift Shop member of the Windom, lol.

 

I stand corrected.  Greenops boothi plushtoyi has a wider distribution than was previously reported in the literature.

Link to comment
Share on other sites

5 hours ago, rew said:

The difference between those two species appears to be primarily in the length of the pygidal lappets, with G. boothi having them longer.  It isn't clear to me where my specimen lies.

 

Greenops boothi: terminal pygidial lappet broad anteriorly, subrectangular, convex posteriorly                         

Greenops barberi: terminal pygidial lappet developed as narrow (tr.) sharply pointed triangle

 

Lieberman, B.S., Kloc, G.J. 1997
Evolutionary and biogeographic patterns in the Asteropyginae (Trilobita, Devonian) Delo, 1935. 
American Museum of Natural History Bulletin, 232:1-127  PDF LINK

 

image.thumb.png.451e84318c1b7039a4713930a5029530.png

 

  • I found this Informative 2

image.png.a84de26dad44fb03836a743755df237c.png

Link to comment
Share on other sites

When I read that paper I have to concede that my bug comes a little closer to G. barberi.  But when I look at various alleged G. boothi and G. barberi specimens on the internet, there's very little consistency.

Link to comment
Share on other sites

There is much confusion on the internet about Greenops and some of the identifications are not reliable.  There are only 2 species of Greenops in Western New York, G. grabaui in the Wanakah Shale and G. barberi in the Windom Shale. As one goes eastward in NY the stratigraphy changes dramatically. The Hamilton Group thickens and many more units are present and multiple species of Greenops occur there.  Greenops boothi does occur in NY but only in Eastern NY in an unnamed unit between the Kashon Shale and the Windom Shale.

  • I found this Informative 5
Link to comment
Share on other sites

1 hour ago, GerryK said:

There is much confusion on the internet about Greenops and some of the identifications are not reliable.  There are only 2 species of Greenops in Western New York, G. grabaui in the Wanakah Shale and G. boothi in the Windom Shale. As one goes eastward in NY the stratigraphy changes dramatically. The Hamilton Group thickens and many more units are present and mutable species of Greenops occur there.  Greenops does occur in NY but only in Eastern NY in an unnamed unit between the Kashon Shale and the Windom Shale.

 

 

Where does the G. barberi fit into the equation then?

Jay A. Wollin

Lead Fossil Educator - Penn Dixie Fossil Park and Nature Reserve

Hamburg, New York, USA

Link to comment
Share on other sites

9 minutes ago, DevonianDigger said:

 

Where does the G. barberi fit into the equation then?

Sorry, thanks for pointing out my error. Corrections are made and now it's OK.

  • I found this Informative 1
Link to comment
Share on other sites

Trilobite #25, the official Trilobite of the Week, is another member of the Acastidae, this one of Eifelian age from Jebel Issoumour, Morocco -- Morocconites malladoides.  I'm pretty sure I got the species right this time because it's the only one in the genus.  This one is famous for the upturned rostrum.   The right eye isn't perfectly preserved but the lenses that are there are easy to see, as is typical of the schizochroal eyes found in the Phacopina.

dorsal-cropped-rotated-small.jpg

dorsolateral-right-small.jpg

right-eye-small.jpg

  • I found this Informative 3
Link to comment
Share on other sites

Now to squeeze in some mid-week trilobites before the middle of the week is gone.  Both of these are Moroccan Devonian phacopidae.  Trilobite #26 Reedops cephalotes, is from the early Devonian (Pragian stage) and was found in the Ihandar Formation of Jebel Issoumour, Morocco.

dorsal-cropped-rotated-small.jpg

left-small.jpg

Link to comment
Share on other sites

Trilobite #27 is the middle Devonian Pedinopariops sp. from Djebel Ou Driss, Morocco.  At least I think it's a Pedinopariops, the various phacopidae with pustulose glabellas are quite similar to one another.  I don't know the species.

dorsal-cropped-rotated-small.jpg

dorsolateral-right-small.jpg

front-small.jpg

Link to comment
Share on other sites

Now for the official trilobite of the week, #28.  This bug was undescribed when I bought it and so far as I know it is still undescribed.  It is an early Devonian acastid from Jebel Issoumour, Morocco that appears to be related to Morocconites.  It is smaller -- the Morocconites malladoides that was last week's trilobite of the week is 7.5 cm long, typical for the species; this bug is about 4.2 cm long, and seems to be typical for its species, although I can't be sure because I've only seen one other specimen for sale.  (This bug seems to be fairly rare.)    The rostrum is straight and needle-like rather than curved upwards, and is a longer proportion of the total body length.

dorsal-small.jpg

dorsolateral-right-small.jpg

Link to comment
Share on other sites

It's time for the midweek bonus trilobite, #29.  This is a nice natural double of early Devonian age from the Haragan Formation of Coal County, Oklahoma, Paciphacops campbelli.  Here we see both bugs and close ups of the two bugs.

pair-small.jpg

large-dorsal-small.jpg

small-dorsal-cropped-rotated-small.jpg

Link to comment
Share on other sites

Now for trilobite #30, the official trilobite of the week.  This is a natural double, Basseiarges mellishae, a small early Devonian lichid from Jorf, Morocco.  The close up here is of the left specimen.

pair-cropped-small.jpg

left-dorsal-cropped-rotated-small.jpg

  • I found this Informative 1
Link to comment
Share on other sites

Here is the other trilobite on the plate.  The eyes are just barely visible as slightly raised bumps on the very front of the head, well separated from the edges of the glabella.

right-dorsal-cropped-rotated-small.jpg

right-front-cropped-small.jpg

Link to comment
Share on other sites

This week's trilobite of the week is #31, Modocia typicalis, of Middle Cambrian age and from the Marjum Formation in the House Range of Utah.  This is a large (2") specimen.  The trilobite has no repair crack, so how did the preparator know to dig deep into the rock to find it?  The trilobite was found ventrally, a flat rock was glued to the ventral side to back it, and then the trilobite was prepared dorsally.  I'm starting to see more bugs with this type of preparation.

 

dorsal-small.jpg

whole-rock-cropped-small.jpg

  • I found this Informative 1
Link to comment
Share on other sites

Wow, that's deep!:trilo: Maybe it has been scanned?

It's a great collection, all those trilobites so well preserved.

"The baneful Dragons, O Seas, are gone: Fiends, 0 Earth, have filled thee with the bones of Defeat and Death."

Link to comment
Share on other sites

If you have the specimen in hand you can easily see that there are two parallel slabs of rock glued together, with the trilobite at the level where the seam is.  So it was clearly found ventrally.  I have one other bug prepared this way, and have seen a couple of other examples not in my collection.;

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...