THE DUDLEY BUG: ROLLED TRILOBITE

A lovely rolled trilobite, Calymene blumenbachii,  from outcrops in the UK. This wee beauty is in the collections of the deeply awesome Theresa Paul Spink Dunn — or perhaps in her daughter Layla's collections as she is quite the budding palaeontologist. This Silurian beauty is from the Homerian, Wenlock Series, Wrens Nest, Dudley, UK.

Calymene blumenbachii, sometimes erroneously spelled blumenbachi, is a species of trilobite found in the limestone quarries of the Wren's Nest in Dudley, England.

Nicknamed the Dudley Bug or Dudley Locust by an 18th-century quarryman, it became a symbol of the town and featured on the Dudley County Borough Council coat-of-arms. Calymene blumenbachii is commonly found in Silurian rocks (422.5-427.5 million years ago) and is thought to have lived in the shallow waters of the Silurian, in low energy reefs.

This particular species of Calymene — a fairly common genus in the Ordovician-Silurian — is unique to the Wenlock series in England and comes from the Wenlock Limestone Formation in Much Wenlock and the Wren's Nest in Dudley. 

These sites seem to yield trilobites more readily than any other areas on the Wenlock Edge, and the rock here is dark grey as opposed to yellowish or whitish as it appears on other parts of the Edge, just a few miles away, in Church Stretton and elsewhere suggesting local changes in the environment in which the rock was deposited. 

The Wenlock Edge quarry is closed now to further collecting but may be open to future research projects. We shall have to wait and see.

HOLLARDOPS: LE MAÎTRE

Hollardops sp. Devonian Trilobite

Hollardops is a genus of trilobite in the order Phacopida that lived during the Eifelian of the Middle Devonian. It was described by Le Maître in 1952 under type species Metacanthina mesocristata. 

The genus underwent reclassification in 1997 and emerged as Hollardops. We find this extinct arthropod in present-day Morocco. They share similarities with Greenops of New York and Canada but are generally larger than most Greenops species.

Hollardops have schizochroal eyes and a glabella that is slightly raised on the surface of the cephalon. Genal spines extend from the cephalon and extend to approximately the 6th thoracic segment.

Hollardops has eleven thoracic segments and also has five pairs of spines extending from the segments of the pygidium. Length ranges from approximately 3 to 9 cm.

Palaeo Coordinates — If you are a keen bean to head out in search of this lovely yourself, head to the Tazoulait Formation at Jbel (Jebel) Oufatène 30.8374368°N 4.9018067°W and Issimour 30.9669834°N 5.0373266°W SE of Alnif, western of Oued Alnif, Ma'ider region, Morocco.

BUENELLUS HIGGINSI FROM GREENLAND

An exceptional example of the Lower Cambrian trilobite Buenellus higginsi from the Sirius Passet Biota, Buen Formation which borders the Arctic Sea along the northernmost coast of Greenland, an island country that is part of the Kingdom of Denmark located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. If you look closely, you can see that this specimen shows preservation of gut.

Buenellus higginsi averages around 5 centimeters or 2 inches. There have been some interesting studies done on these trilobites regarding predation. 

The predation scars are typically arcuate and show evidence of repair, with distortion of the healed area

It is a prominent member of the Sirius Passet fauna. If you find one, you find oodles of them in the outcrop. Buenellus higginsi is the only known species in the genus Buenellus as the genus is monotypic.

LYSAKER MEMBER TRILOBITE

Niobe schmidti (Balashova, 1976)

This gorgeous trilobite is an exceptionally well-preserved Niobe schmidti (Balashova, 1976) from middle Ordovician limestone deposits of the Huk Formation, Lysaker member near Oslo, Norway. 

The limestones of the Huk Formation have an extreme geological history and fossils from this formation are usually very difficult to prepare. 

The beige/grey limestones are often heavily cemented to the shelly material, which can be quite fragile.

The rich chocolate coloured specimen you see here was no exception. It presented many challenges in its 26 hours of preparation but each of these was overcome by the patience and skill of Paul Freitag Wolvers at Freitag Fossils. 

I have added a link below with a series of photos so you can walk through the preparation process step by step with Paul. If you have a special specimen you would like prepped, I highly recommend you contact him. His work is outstanding.

Superb prep of this Niobe schmidti (Balashova, 1976)

The shell was partly hollow, very fragile and stuck firmly to the matrix. The positive was assembled from two pieces and much of the shell of the left half of the trilobite had to be transferred over from the negative — no small feat. 

Despite these challenges, the final result is superb. This Niobe schmidti is a museum-quality specimen with exquisite preservation. You can clearly see the lovely terrace lines, pores and eye lenses are excellent to study.  

This specimen hails from the middle Ordovician. The Ordovician lasted almost 45 million years, beginning 488.3 million years ago and ending 443.7 million years ago. 

It was the time in our Earth's history when the area north of the tropics was almost entirely underwater and most of the world's land was collected into the southern supercontinent of Gondwana. Throughout the Ordovician, Gondwana slowly shifted towards the South Pole and much of it remained submerged under an ancient ocean.

Niobe schmidti (Balashova, 1976)

At the time that this fellow was making a living in our ancient seas, he would have been joined by a diverse community of marine invertebrates —graptolites, fellow trilobites, brachiopods and the early vertebrate conodonts. 

These marine communities were joined by red and green algae, primitive fish, cephalopods, corals, crinoids, and gastropods. 

We also find stunning tetrahedral spores similar to those of primitive land plants which tell us who was living on the land at the time.

One of the first specimens of this lovely species I had the pleasure to see was from the Voybokalo Quarry near St. Petersburg in Russia. These outcrops are part of the Kunda Horizon, Lower Ordovician, Asaphus expansus zone and run roughly 468 million years old. 

From the Lower to Middle Ordovician, the Earth was enjoying a mild, humid climate — the weather was warm and the atmosphere contained a significant amount of moisture. 

Once Gondwana finally settled on the South Pole during the Upper Ordovician, massive glaciers formed. These drained the shallow seas and ocean levels dropped. By the end of the Ordovician, 60% of all marine invertebrates and 25% of all life on Earth disappeared as part of the Ordovician mass extinction event. We enjoy many of those species now only as fossils and if we are lucky, preserved in remarkable detail.

Photos & collection: Mark Wolvers. Preparation: Paul Freitag, Freitag Fossils. Specimen: 5.5 cm (2.16 inches). You can see some amazing photos of the transformation of this trilobite throughout Paul's preparation process here: https://freitag-fossils.com/en/niobe-schmidti/

If you click on any of the images, you can see them enlarged to take in all the wonderful detail. 

Reference: UCMP Berkeley / https://ucmp.berkeley.edu

ANCIENT LIFE IN THE EAST KOOTENAYS: ORYGMASPIS SPINULA

Orygmaspis (Parabolinoides) spinula

This calcified beauty is Orygmaspis (Parabolinoides) spinula (Westrop, 1986) an Upper Cambrian trilobite from the McKay Group near Tanglefoot Mountain in the Kootenay Rockies. 

Orygmaspis is a genus of asaphid trilobite with an inverted egg-shaped outline, a wide headshield, small eyes, long genal spines, 12 spined thorax segments and a small, short tail shield, with four pairs of spines.

The outline of the exoskeleton Orygmaspis is inverted egg-shaped, with a parabolic headshield — or cephalon less than twice as wide as long. 

The glabella, the well-defined central raised area excluding the backward occipital ring, is ¾× as wide as long, moderately convex, truncate-tapering, with 3 pairs of shallow to obsolete lateral furrows. 

The occipital ring is well defined. The distance between the glabella and the border (or preglabellar field) is ±¼× as long as the glabella. This fellow had small to medium-sized eyes, 12-20% of the length of the cephalon. These were positioned between the front and the middle of the glabella and about ⅓ as far out as the glabella is wide. 

The remaining parts of the cephalon, the fixed and free cheeks — or fixigenae and librigenae — are relatively flat. The fracture lines or sutures — that separate the librigenae from the fixigenae in moulting — are divergent just in front of the eyes. These become parallel near the border furrow and strongly convergent at the margin. 

From the back of the eyes, the sutures bend out, then in, diverging outward and backward at approximately 45°, cutting the posterior margin well within the inner bend of the spine — or opisthoparian sutures. 

The thorax or articulating middle part of the body has 12 segments. The anteriormost segment gradually narrows into a sideward directed point, while further to the back the spines are directed outward and the spine is of increasing length up until the ninth spine, while the spine on the tenth segment is abruptly smaller, and 11 and 12 even more so. 

This fellow has a wee pygidium or tail shield that is only about ⅓× as wide as the cephalon. It is narrowly transverse about 2× wider than long. Its axis is slightly wider than the pleural fields to each side, and has up to 4 axial rings and a terminal and almost reaches the margin. Up to 4 pleural segments with obsolete interpleural grooves and shallow pleural furrows. The posterior margin has 3 or 4 pairs of spines, getting smaller further to the back. 

References:

Chatterton, Brian D. E.; Gibb, Stacey (2016). Furongian (Upper Cambrian) Trilobites from the McKay Group, Bull River Valley, Near Cranbrook, Southeastern British Columbia, Canada; Issue 35 of Palaeontographica Canadiana; ISBN: 978-1-897095-79-9

Moore, R.C. (1959). Arthropoda I - Arthropoda General Features, Proarthropoda, Euarthropoda General Features, Trilobitomorpha. Treatise on Invertebrate Paleontology. Part O. Boulder, Colorado/Lawrence, Kansas: Geological Society of America/University of Kansas Press. pp. O272–O273. ISBN 0-8137-3015-5.

ANCIENT FOSSIL TRACKWAYS

Trilobite and Sea Scorpion Fossil Trackways

This is a very interesting block with wee trace fossil trackways from our Mississippian seas some 359.2 million to 318.1 million years ago. 

It shows a nice combination of Cruziana fossil trilobite trackway and eurypterid (sea scorpion) or horseshoe crab trackway on the same matrix. 

When we use the term Cruziana, we are not referring to the trilobite species, but to the particular shape and form of the trackway. 

In this case, elongate, bilaterally symmetrical burrows preserved along the bedding plane with repeated striations that are mostly oblique to the long dimension. I like to picture a teeny, tiny painter or sculpture with a small putty knife making angled cuts along a line or a wave motion to create a small curved line. Very showy skate skiing is another good visual. Sadly, neither is the case. While a Cruziana trace fossil is most often associated with trilobites, it can be made by other arthropods. 

When we see trace fossils — preserved tracks or other signs of behaviour from our marine friends living on the seafloor — they are generally from their furrowing, resting, emerging, walking or striding. They provide a glimpse of how these ancient sea creatures moved about to make a living. 

Trilobite and Sea Scorpion Fossil Trackways

This busy 4 1/2" x 3 1/2" x 1 1/4" block hails from the Tar Springs Formation in Perry County, Indiana, USA, and is in the collections of the deeply awesome David Appleton.

The Tar Springs Formation is recognized on the surface from southwestern Orange County to the Ohio River and is known in the subsurface from central Martin County southwestward (Gray, 1970, 1986).

In Indiana, the Tar Springs Formation is primarily shale, but it also contains scattered thin beds of limestone and massive local lenses of sandstone that on outcrop are differentiated as the Tick Ridge Sandstone Member (Gray, 1986). The formation ranges in thickness from about 70 ft (21 m) to more than 150 ft (46 m) in central Posey County and in southwestern Gibson County (Droste and Keller, 1995). Commonly sandstone predominates in those areas where the Tar Springs is as much as 150 ft (46 m) thick (Droste and Keller, 1995).

TRACKING THROUGH THE CAMBRIAN

Pterocephalia norfordi, McKay Group

A lovely Pterocephalia norfordi trilobite from Upper Cambrian, Furongian strata of the McKay Group, East Kootenay Region, southeastern British Columbia, Canada. 

The McKay Group has been explored extensively these past few years by Chris New and Chris Jenkins of Cranbrook, British Columbia. 

Together, these two avid trilobite enthusiasts have opened up considerable knowledge on the exposures, collaborating with researchers Brian Chatterton and Rudy Lerosey-Aubril. They have unearthed many new specimens and several new species. 

Pterocephalia from this region are relatively common. We also find Wujiajiania lyndasmithae along with a host of other Upper Cambrian goodies. 

I collected dozens of well-preserved fully articulated specimens over the course of a week in August 2020, walking in the sacred lands of the Ktunaxa or Kukin ʔamakis First Nations. 

My eyes were good enough to find the specimens themselves, but not as refined as those of Chris Jenkins who spotted the unusual preservation of the embedded gut tract. Brian Chatterton et al. published on it in 1994 and have been following it up year upon year with paper after paper out of these localities. 

Rudy Lerosey-Aubril published a paper in 2017 on phosphatized gut remains — relatively common in this taxon at this site. Lerosey-Aubril’s paper was on an aglaspidid, a combjelly, and the gut of another trilobite. 

Skeletal remains of trilobites are abundant in Palaeozoic rock but soft parts are rarely preserved. 

There have been a few papers on trilobite gut remains from Canada and on abundant trilobite faunas of the Kaili Formation of Guizhou, China. 

The Kaili contains one of the earliest middle Cambrian Burgess Shale-type deposits, sharing many faunal elements with the older Chengjiang Biota (Chen 2004; Hou et al. 2004) and the younger Burgess Shale Biota (Briggs et al. 1994). 

The biota, facies description, and regional stratigraphy of the Kaili Biota were discussed and reviewed in Zhao et al. (2002, 2005) and Lin et al. (2005). 

Their colleagues (Zhao et al. 1994b, 1996, 1999, 2001, 2002) have beautifully illustrated many Kaili arthropods with soft-part preservation, but most of their systematic descriptions are yet complete.

References: Chatterton BD, Johanson Z, Sutherland G. 1994. Journal of Paleontology 68:294-305. 

Lin, Jih-Pai. (2007). Preservation of the gastrointestinal system in Olenoides (Trilobita) from the Kaili Biota (Cambrian) of Guizhou, China. Memoirs of the Association of Australasian Palaeontologists. 33. 179-189. 

Top Photo: This specimen was collected by Dan Bowden and photographed by the Huntress. It has been checked for the dark telltale signs of phosphatized gut remains — sadly no luck!

Middle Photo: Warm summer light atop the mountains and my temporary home-sweet-home. Bottom Photo: Upper Cambrian collecting beds beneath Tanglefoot Mountain, McKay Group, East Kootenay Region, British Columbia, Canada.

LOWER CAMBRIAN EAGER FORMATION

This specimen of a mature olenellid trilobite, Wanneria dunnae, is from the Lower Cambrian Eager Formation of British Columbia. 

He is from the Rifle Range outcrop near Cranbrook where you can find numerous fragments and complete specimens of the olenellid trilobites Ollenellus sp. and the larger, more robust Wanneria sp. you see here. 

The site outcrops at a few locations as you head east out of Cranbrook towards Fort Steele. 

The first trilobites were discovered with the building of the Kootenay Highway connecting Cranbrook to Fort Steele and beyond. Several other localities, including the outcrops at the Silhouette Rife Range — which is literally on a Rifle Range where folks go to shoot at things — is a shade older than the Middle Cambrian Burgess Shale but the fauna here is much less varied. 

The site has been known and collected since the 1920s. Back in the day, fossil collecting was a family affair with folks heading out in their lightly coloured finery to picnic and surface collect the eroding exposures. Cranbrook local, Clement Hungerford Pollen was an engineer and avocational palaeontologist. 

He promoted collecting the exposures of the Eager Formation around 1921. As a pedigreed Englishman of considerable means, he had invested in the Kootenay Central Railway, revitalizing the town by opening up railway access within the region.

Olenellus ricei, Eager Formation

Olenellus is an extinct genus of redlichiid trilobites, with species of average size (about 5 centimetres or 2.0 inches long). He lived during the Botomian and Toyonian stages, Olenellus-zone, 522 to 510 million years ago, in what is currently North America, part of the paleocontinent Laurentia.

These extinct arthropods are common in Early Cambrian rocks — 542 million to 521 million years old — and thus a useful guide fossil for the Early Cambrian. 

Olenellus had a well-developed semi-circular head, large and crescentic eyes, and a poorly developed, small tail. Telltale features are his fifteen body segments with the third being much longer than the others. The fellow you see had a bit of his tail crushed as he turned to stone.

Trilobites were amongst the earliest fossils with hard skeletons. While they are extinct today, they were the dominant life form at the beginning of the Cambrian and it is what we find as the primary fossil fauna in the Eager Formation. The Eager Formation has produced many beautifully preserved Wanneria, abundant Olellenus and a handful of rare and treasured Tuzoia. The shale matrix lends itself to amazing preservation. The specimens of Wanneria from here are large. Some are up to thirteen centimetres long and ten centimetres wide. You find a mixture of complete specimens and head impressions from years of perfectly preserved moults.

NIOBE SCHMIDTI OF NORWAY

Niobe schmidti (Balashova, 1976)

This gorgeous trilobite is an exceptionally well-preserved Niobe schmidti (Balashova, 1976) from middle Ordovician limestone deposits of the Huk Formation, Lysaker member near Oslo, Norway. 

The limestones of the Huk Formation have an extreme geological history and fossils from this formation are usually very difficult to prepare. 

The beige/grey limestones are often heavily cemented to the shelly material, which can be quite fragile.

The rich chocolate coloured specimen you see here was no exception. It presented many challenges in its 26 hours of preparation but each of these was overcome by the patience and skill of Paul Freitag Wolvers at Freitag Fossils. 

I have added a link below with a series of photos so you can walk through the preparation process step by step with Paul. If you have a special specimen you would like prepped, I highly recommend you contact him. His work is outstanding.

Superb prep of this Niobe schmidti (Balashova, 1976)

The shell was partly hollow, very fragile and stuck firmly to the matrix. The positive was assembled from two pieces and much of the shell of the left half of the trilobite had to be transferred over from the negative — no small feat. 

Despite these challenges, the final result is superb. This Niobe schmidti is a museum-quality specimen with exquisite preservation. You can clearly see the lovely terrace lines, pores and eye lenses are excellent to study.  

This specimen hails from the middle Ordovician. The Ordovician lasted almost 45 million years, beginning 488.3 million years ago and ending 443.7 million years ago. 

It was the time in our Earth's history when the area north of the tropics was almost entirely underwater and most of the world's land was collected into the southern supercontinent of Gondwana. Throughout the Ordovician, Gondwana slowly shifted towards the South Pole and much of it remained submerged under an ancient ocean.

Niobe schmidti (Balashova, 1976)

At the time that this fellow was making a living in our ancient seas, he would have been joined by a diverse community of marine invertebrates —graptolites, fellow trilobites, brachiopods and the early vertebrate conodonts. 

These marine communities were joined by red and green algae, primitive fish, cephalopods, corals, crinoids, and gastropods. 

We also find stunning tetrahedral spores similar to those of primitive land plants which tell us who was living on the land at the time.

One of the first specimens of this lovely species I had the pleasure to see was from the Voybokalo Quarry near St. Petersburg in Russia. These outcrops are part of the Kunda Horizon, Lower Ordovician, Asaphus expansus zone and run roughly 468 million years old. 

From the Lower to Middle Ordovician, the Earth was enjoying a mild, humid climate — the weather was warm and the atmosphere contained a significant amount of moisture. 

Once Gondwana finally settled on the South Pole during the Upper Ordovician, massive glaciers formed. These drained the shallow seas and ocean levels dropped. By the end of the Ordovician, 60% of all marine invertebrates and 25% of all life on Earth disappeared as part of the Ordovician mass extinction event. We enjoy many of those species now only as fossils and if we are lucky, preserved in remarkable detail.

Photos & collection: Mark Wolvers. Preparation: Paul Freitag, Freitag Fossils. Specimen: 5.5 cm (2.16 inches). You can see some amazing photos of the transformation of this trilobite throughout Paul's preparation process here: https://freitag-fossils.com/en/niobe-schmidti/

If you click on any of the images, you can see them enlarged to take in all the wonderful detail. 

Reference: UCMP Berkeley / https://ucmp.berkeley.edu

CRUZIANA TRILOBITE AND ANCIENT FOSSIL TRACKWAYS

Trilobite and Sea Scorpion Fossil Trackways

This is a very interesting block with wee trace fossil trackways from our Mississippian seas some 359.2 million to 318.1 million years ago. 

It shows a nice combination of Cruziana fossil trilobite trackway and eurypterid (sea scorpion) or horseshoe crab trackway on the same matrix. 

When we use the term Cruziana, we are not referring to the trilobite species, but to the particular shape and form of the trackway. 

In this case, elongate, bilaterally symmetrical burrows preserved along the bedding plane with repeated striations that are mostly oblique to the long dimension. I like to picture a teeny, tiny painter or sculpture with a small putty knife making angled cuts along a line or a wave motion to create a small curved line. Very showy skate skiing is another good visual. Sadly, neither is the case. While a Cruziana trace fossil is most often associated with trilobites, it can be made by other arthropods. 

When we see trace fossils — preserved tracks or other signs of behaviour from our marine friends living on the seafloor — they are generally from their furrowing, resting, emerging, walking or striding. They provide a glimpse of how these ancient sea creatures moved about to make a living. 

Trilobite and Sea Scorpion Fossil Trackways

This busy 4 1/2" x 3 1/2" x 1 1/4" block hails from the Tar Springs Formation in Perry County, Indiana, USA, and is in the collections of the deeply awesome David Appleton.

The Tar Springs Formation is recognized on the surface from southwestern Orange County to the Ohio River and is known in the subsurface from central Martin County southwestward (Gray, 1970, 1986).

In Indiana, the Tar Springs Formation is primarily shale, but it also contains scattered thin beds of limestone and massive local lenses of sandstone that on outcrop are differentiated as the Tick Ridge Sandstone Member (Gray, 1986). The formation ranges in thickness from about 70 ft (21 m) to more than 150 ft (46 m) in central Posey County and in southwestern Gibson County (Droste and Keller, 1995). Commonly sandstone predominates in those areas where the Tar Springs is as much as 150 ft (46 m) thick (Droste and Keller, 1995).

TRILOBITES: DARLINGS OF THE FOSSIL RECORD

Trilobites are the darlings of most fossil collectors. These diverse beauties are an extinct group of marine arthropods that first appeared in the Early Cambrian. 

They left many beautifully preserved examples of their three-lobed exoskeletons in the fossil record.

Trilobites — in all their many wonderful forms — lived in our ancient oceans for more than 270 million years. The last of their lineage went extinct at the end of the Permian, 252 million years ago.