My trilobite of the week.

[piranha]

11 hours ago, rew said:

Trilobite of the week #242 is Wallacia sp. of Middle Silurian age from the Rytterrakker Formation at Lier, Norway. 

 

The Norwegian species is Wallacia jaanussoni. 

 

It is distinguished from all the other species of Wallacia by the long caudal spine (mucro). [pardon the telson!]

 

Ramsköld, L., Edgecombe, G.D. 1994

Revision of the Silurian Encrinurine Trilobite Wallacia Lamont 1978, With Species from Gotland and Canada.

Paläontologische Zeitschrift, 68(1/2):89-115  PDF LINK

[rew]

Thank you.  I can remove the "sp." on my label.

[rew]

Trilobite of the week #243 is Proetopeltis neglecta of Early Devonian (Emsian) age, from the Red Cliff formation at Hamar Laghdad, Morocco.  This is another little proetid, the type of bug I get wrong most often, so don't believe the identification until Piranha says it's okay.

 

Look past the dust specks and cruft on the eye and you can just make out the lenses of the holochroal eyes.

 

[rew]

Trilobite of the week 244 is Acanthopyge estevei of Early Devonian (Pragian stage) age, from the Ihander Formation at Atchana, West of D'jbel Oufaténe, Morocco.  This is a small species, only about an inch around the curve.  As is common with this species it is in highly retroflexed position with the head pointing straight up.  The preparator took advantage of this to expose the hypostome.  The optical surface on the right side is well preserved but I see no hint of the lenses, and didn't expect to see any on a lichid trilobite.

 

 

[piranha]

11 hours ago, rew said:

Trilobite of the week 244 is Acanthopyge estevei of Early Devonian (Pragian stage) age, from the Ihander Formation at Atchana, West of D'jbel Oufaténe, Morocco. 

 

 

This trochurine lichid genus has been revised.

 

Huginarges is the new name for the taxa previously classified as Acanthopyge (Belenopyge) and the junior homonym 'Lobopyge'.

 

"Several potential lineages are recognised here that originated mainly from an Ordovician–Devonian rootstock of a paraphyletic Huginarges. The close relationship
between Acanthopyge and Huginarges that was assumed by previous workers is adopted although a distinction between generic and subgeneric ranks is not attempted in the present paper. Pygidia are illustrated, because these are the most distinctive for the majority of Devonian taxa involved."

 

 

Van Viersen, A.P. 2021. Systematics of Devonian Trochurine Trilobites (Lichidae).

Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 300(2):175-187  PDF LINK

[rew]

So this bug is now Huginarges estevei.  Is the Oklahoma trilobite Acanthopyge consanguinea now Huginarges consanguinea?   It has a pygidium very similar to that of Huginarges estevei.   Am I correct that Acanthopyge haueri is still in the genus Acanthopyge?

Edited September 7, 2022 by rew

[piranha]

2 hours ago, rew said:

Is the Oklahoma trilobite Acanthopyge consanguinea now Huginarges consanguinea?  Am I correct that Acanthopyge haueri is still in the genus Acanthopyge?

 

Affirmative x 2 =  

[rew]

I am fortunate to have one of the world's trilobite experts sorting out my collection.  (Not that I have an Acanthopyge haueri in my collection -- I only wish I did.)

[rew]

Trilobite of the week #245 is Dikelokephalina brenchleyi, of Early Ordovician age, from the Fezouata Shale at Ouled Slimane, Zagora area, Morocco.  This genus is readily identified by its double pointed pygidium.  Every trilobite collector should have at least one big bug.  This is mine.  It is 28.7 cm (11 1/4") long.  It's probably bigger in real life than it appears on your screen.  This is also my only trilobite in the family Dikelokephalinidae.  There are patches of missing shell on the head; with fossils we have to take what nature gives us.

 

 

Edited September 11, 2022 by rew

[rew]

Last week I showed you my biggest trilobite.  Trilobite of the week #246 is tied with another species as being my smallest trilobite.

It is Anglagnostus dux of Early Ordovician age, from the Tremadoc Series, Migneintian Stage at Shineton, Shropshire, UK.  This is my only Ordovician agnostid and the only member of the family Agnostidae in my collection.  It is only 3.5 mm long.  The Dikelokephalina brenchleyi weighed about half a million times as much.

[rew]

Trilobite #247 is one of my more humble specimens.  It is Phacopidina micheli of Early Ordovician age from the Valongo Formation at Beloir, Portugal.  This is an internal mold, and although you can see the outline of the entire head the front left and front center of the head is chipped away.

 

Despite the genus name this is not in the Phacopidae but is instead in the Acastidae.

 

And despite being a naked trilobite, there is some evidence of the lenses in the schizochroal eyes.

 

 

[rew]

Trilobite of the week #248 is Isabelinia glabrata of Early Ordovician age from the Valongo Formation at St. Pedro de Cova, Portugal.  This is another member of the Asaphidae.

 

[rew]

Trilobite of the week #249 is Ninglangia sinensis, of Ordovician age (Dariwillian Stage) from the Llanvirn Series at Baoshan, Yunnan, China.

 

This is another member of the Illaenidae.

 

 

[Notidanodon]

ive said this before but this is an amazing thread   what a collection

[rew]

Trilobite of the week #250 is Perrector falloti (= Resserops falloti = Richterops falloti) of Early Cambrian age from the Amouslek Formation, Tiout Member located south of Tazemmourte, Morocco.  This species has a poor calcified carapace, the preparator left it higher than the surrounding rock, making it easier to see where the trilobite ends and the rock begins.

 

It's closest relative in my collection is the Conomicmacca boutiouiti.

 

Edited October 15, 2022 by rew

[rew]

Trilobite of the week #251 is Elvinia roemeri of Late Cambrian age from the McKay Formation at Cranbrook, British Columbia, Canada.

 

Edited October 22, 2022 by rew

[Sjfriend]

Many more specimens for us all to drool over 

[rew]

Trilobite of the week #252 is Eldredgeops rana of Middle Devonian age from the Silica Formation at Sylvania, Ohio.  This is a classic American member of the Phacopidae.  Some of you have no doubt dug up your own specimens of this bug.  This specimen is larger than most - it is 8 cm long.

[rew]

Trilobite of the week #253 is Eodalmanitina destombesi of Middle Ordovician age (Dariwillian Stage) from the Llanvirn Series of the Valongo Formation, at St. Pedro de Cova, Portugal.  The rock in the Valongo Formation is stretched in one direction and compressed in the other. Fossils within it are stretched, compressed or skewed depending on their orientation. This trilobite is skewed. Despite the very flattened preservation the eyes pop out and the lenses of the schizochroal eyes are visible. The tail spine is readily visible.   You'll find prettier Dalmanitid trilobites from the limestone formations at Black Cat Mountain or Morocco, but you won't find this species in those rocks.

 

[SpeedThrash]

On 6/5/2019 at 10:54 PM, Kermit72 said:

I'm new to the forum, you have some amazing trilobites! I recently acquired a Hallardrops and Scabriscutellum with excellent eyes 

I'm new to all this, why is the eye a different color? Is that artificially added later on? Looks really cool overall!

[rew]

Newbie, that's Hollardops, and those eyes look real to me.  Sometimes some iron oxide in the eyes give them an orange color when the rest of the trilobite is black.  That's a feature, not a bug.

[rew]

Trilobite of the week #254 is either Malungia laevigata, if you believe the AMNH trilobite gallery has it right, or Dolerolenus laevigata, if Sam Gon's site is correct (its has Malungia as a junior synonym of Dolerolenus).  In any case, it is a Redlichid trilobite of Early Cambrian age from the Lowermost Hongjingshao Formation near Kunming, Yunnan, China.  At 1.1 cm this easily qualifies as my smallest Redlichid trilobite, the AMNH gallery has a monster 3 cm specimen.  This is my only trilobite in the family Dolerolenidae.

 

[piranha]

On 11/13/2022 at 2:13 AM, rew said:

Trilobite of the week #254 is either Malungia laevigata, if you believe the AMNH trilobite gallery has it right, or Dolerolenus laevigata, if Sam Gon's site is correct (its has Malungia as a junior synonym of Dolerolenus). 

 

 

The literature has been divided over the years between Malungia LU 1961 and Jell & Adrain 2003 that lists Malungia as a j.s.s. of Dolerolenus. However, the most recent paper (Hou et al. 2019) to address this issue with a formal description, follows the Treatise (1997) that classified Malungia as a subgenus: Dolerolenus (Malungia) laevigata.

 

 

Hou, J.B., Yang, J., Zhang, X.G., Hughes, N.C., Lan, T. 2019
Trilobite-Based Biostratigraphy of the Xiaoshiba Lagerstätte.
Fossils and Strata, 64:173-191

 

 

 

Lu, Y. 1961
New Lower Cambrian Trilobites from Eastern Yunnan.
Acta Palaeontologica Sinica, 9(4):299-325

 

 

 

Whittington, H.B., Chatterton, B.D.E., Speyer, S.E., Fortey, R.A., Owens, R.M., Chang, W.T., Dean, W.T., Jell, P.A., Laurie, J.R.,

Palmer, A.R., Repina, L.N., Rushton, A.W.A., Shergold, J.H., Clarkson, E.N.K., Wilmot, N.V., Kelly, S.R.A. (Kaesler, R.L. ed.) 1997
Treatise on Invertebrate Paleontology, Part O, Arthropoda 1, Trilobita, Revised. Geological Society of America & University of Kansas Press, 530 pp.

 

Jell, P.A., Adrain, J.M. 2003
Available Generic Names for Trilobites.
Queensland Museum Memoirs, 48(2):331-551  PDF LINK

[Scylla]

On 11/13/2022 at 5:02 AM, rew said:

Newbie, that's Hollardops, and those eyes look real to me.  Sometimes some iron oxide in the eyes give them an orange color when the rest of the trilobite is black.  That's a feature, not a bug.

But it is a feature of the bug.

[rew]

Trilobite #255 is Palaeolenus lantenoisi, of Early Cambrian age, from the Wulongqing Formation near Kunming, Yunnan, China.  This humble bug is relatively common, but it is my only member of the family Palaeolenidae.