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Chotecops ferdinandi (Kayser, 1880)
Chot = spouse, consort A ventral specimen with incredible preservation of hypostome, appendages and setae. Chotecops are the most abundant arthropod of the Hunsruck Slate.
Hunsrück Slates 2019 408–400 Mya old
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Nahecaris stuertzi (Jaekel, 1921)
Nahe = tributary of the Rhine River. Caris = shrimp The most common non-trilobite arthropod. The large bivalved shield covers the head, thorax, and anterior segments of the abdomen. Body length is up to 150-200mm. Once again, this specimen is a true museum quality one, so I am gonna give it 5-star rarity.
Hunsrück Slate 2018 408–400 Mya old
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Jaekelaster petaliformis (Stürtz 1899)
Petalos = broad, flat; having the form of a petal, corresponding to the lance-shaped arms. The arm length is 55-135mm Extremely rare type of Stenuroids
Hunsrück Slate 2022 408–400 Mya old
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Palaeoisopus problematicus (Broili, 1928)
Palaios = old. Isos = podus = with the same legs (isopod). Problema = problem. Palaeoisopus is the largest sea spider or the Hunsruck Slate. Body length is 40-142mm. The first limb span reaches up to 320mm
Hunsrück Slate 408–400 Mya old GERMANY
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Undescribed frontal appendage
This is a very rare frontal appendage from an unknown arthropod. It might belongs to a great-appendage one or a radiodontant.
Beecher's Trilobite Bed 2019 460 Mya old
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Undescribed Marrellid Marrellomorph
A very enigmatic marrellid arthropod that discovered from the BTB site. The overall exoskeleton shape looks quite similar to Furca bohemica from Letna Fm and Furca sp. from Fezouata Fm. Unfortunately there are no more soft-tissues preserved in this fossil.
Beecher's Trilobite Bed 2020 460 Mya old
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Undescribed vachonisiids
An possible acercostracan marrellomorph from the Ordovician Beecher’s Trilobite. Similar features are also found in Xylokorys chledophilia from the Silurian of England, and Vachonisia rogeri from the Devonian of Germany, indicating acercostracan affinities for this new species. This taxon is characterised by the possession of a cordiform dorsal carapace with at least two pairs of marginal spines that covering the posterior body. The head comprises two stalked eyes. The trunk possesses more than 25 pairs of delicate, almost filamentous appendages.
Beecher's Trilobite Bed 2019 460 Mya old
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Undescribed frontal appendages of Caryosyntrips sp.
Caryosyntrips ("nutcracker") is an extinct genus of radiodont which existed in Canada and the United States during the middle Cambrian. Caryosyntrips is known only from a handful of 14-segmented frontal appendages, which resemble nutcrackers, recovered from the Burgess Shale Formation. It was first named by Allison C. Daley, Graham E. Budd in 2010 and the type species is Caryosyntrips serratus. The specimen showing here is probably the first Ordovician Caryosyntrips ever found globally.
Beecher's Trilobite Bed 2019 460 Mya old
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Furca bohemica Fritsch, 1908
The enigmatic marrellomorph arthropod Furca bohemica from the Upper Ordovician Letná Formation, is redescribed. Based on existing museum specimens and new material collected from the southern slope of Ostrý Hill (Beroun, Czech Republic), the morphology and taphonomy of F. bohemica is reappraised and expanded to produce a new anatomical interpretation. The previously distinct taxa F. pilosa and Furca sp., are synonymised with F. bohemica, the latter being represented by a tapho−series in which decay has obscured some of the diagnostic features. A cladistic analysis indicates close affinities between F. bohemica and the Hunsrück Slate marrellomorph Mimetaster hexagonalis, together forming the Family Mimetasteridae, contrary to previous models for marrellomorph internal relationships. As with other representatives of the group, the overall anatomy of F. bohemica is consistent with a benthic, or possibly nektobenthic, mode of life. The depositional setting of the Letná Formation indicates that F. bohemica inhabited a shallow marine environment, distinguishing it palaeoecologically from all other known marrellomorphs, which have been reported from the continental shelf.
Letna Formation 2018 Late Ordovician
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Duslia insignis Jahn, 1893
Originally described by Jahn (1983) as a chitnoid mollusc. It was recognized as an arthropod by Pilsbry (1900) and Fritsch (1908). It also shows some morphological analogies with Cheloniellon, Pseudoarthron and Triopus. Duslia inhabited a nearshore shallow marine environment and was probably a benthic animal which lived buried in sandy substrate near the sediment-water interface.
Letna Formation 2020 Late Ordovician
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Beckwithia typa (Resser, 1931)
This specimen is a rare example of the aglaspid Beckwithia. Aglaspids resemble the modern-day horseshoe crabs, and contain as the most famous member the Beckwithia typa shown here, a monsterous creature reaching up to some 20 cm in overall length that is thought to have Beckwithia was named after Frank Beckwith, editor and publisher of the Millard County Chronicle of Delta, Utah in the early to middle 1900s, a man with a passion for trilobites. Aglaspids are thought by some scientists to have made the The aglaspidids survived into the Early Ordovician but died out by the end of the period. It has been proposed that they are related to the ancestors of horseshoe crabs and arachnids.
Weeks Upper Middle Cambrian, Cenomanian Stage USA
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Cedaria minor (Walcott, 1916)
This trilobite is a member of the family Cedariidae known as Cedaria minor. Cedaria is a small, rather flat trilobite with an oval outline, a headshield and tail shield of approximately the same size, 7 articulating segments in the middle part of the body and spines at the back edges of the head shield that reach halflength of the body. Cedaria lived during the early part of the Upper Cambrian (Dresbachian), and is especially abundant in the Weeks Formation.
Weeks Upper Middle Cambrian, Cenomanian Stage USA
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Cedarina schachti n. sp.
Diagnosis Frontal area and preglabellar field long; anterior border evenly anteriorly arcuate; anterior sections of facial suture strongly anteriorly divergent; palpebral lobes large; pygidium relatively narrow and long. Etymology The species is named in honour of Robert Schacht, who collected and donated the holotype and one of the paratype specimens. source: The Marjuman trilobite Cedarina Lochman: thoracic morphology, systematics, and new species from western Utah and eastern Nevada, USA The thorax of C. schachti has ten segments. The segments have a simple morphology (Fig. 5), featuring a well impressed pleural furrow with a transverse course and distal pleural regions that are tapered into blunt, posteriorly directed pleural spines. The eighth segment bears a long median axial spine. None of the other segments bear any axial nodes or spines. This morphology is all but identical to that seen in the articulated "richardsonellines" cited above. The only difference is that the remopleuridids have two additional thoracic segments posterior to the spine-bearing eighth.
Weeks Upper Middle Cambrian, Cenomanian Stage USA
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Deiracephalus aster (Walcott, 1916)
Species of Deiracephalus Resser, 1935, are rare elements in most Guzhangian (upper Marjuman) trilobite faunas of Laurentian North America, and are characterized by striking cephalic spinosity that includes very long genal and occipital or preoccipital glabellar spines. Almost all previous reports of the genus have assigned sclerites to two species, Deiracephalus aster (Walcott, 1916) and Deiracephalus unicornis Palmer, 1962. They usually range up to at least 20mm in length, has a large occipital spine and a medial spine of siilar size on each of 10 thoracic segements. Large, outwardly and backwardly directed genal spines are unusual in arsing from just inside the cephalic border rather than from the outer border surface, as in most polymerid trilobites.
Weeks Upper Middle Cambrian, Cenomanian Stage USA
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Genevievella granulata (Walcott, 1916)
Genevievella is a genus of trilobites with a short inverted egg-shaped outline, a wide headshield, small eyes, and long genal spines. The backrim of the headshield is inflated and overhangs the first of the 9 thorax segments. The 8th thorax segment from the front bears a backward directed spine that reaches beyond the back end of the exoskeleton. It has an almost oval tailshield with 5 pairs of pleural furrows. It lived during the Upper Cambrian in what are today Canada and the United States.
Weeks Upper Middle Cambrian, Cenomanian Stage USA
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