Graptolites from the Wheeler and Marjum Formations (Cambrian, Series 3) of Utah

Abstract

Specimens from the Wheeler and Marjum Formations of Utah comprising an elongate stipe with freely projecting conical thecae are described as dithecoid graptolites, the first reported from these units. The Wheeler Shale specimens, assigned to Archaeolafoea monegettae (Chapman, 1919), provide the first record of Archaeolafoea Chapman, 1919 from the Cambrian of Laurentia and show clear fusellar structure in backscattered electron images, confirming a graptolite affinity for this taxon. Mastigograptus sp., described on the basis of a single well-preserved specimen from the Marjum Formation, shows for the first time in a Cambrian mastigograptid an arrangement of thecae similar to that known for Ordovician representatives of the genus.

The hydroid fossil record and analytical techniques for assessing the affinities of putative hydrozoans and possible hemichordates

“…Lastly, misidentification of hemichordates as leptomedusans due to their mutual possession of thecae may have inflated the number of reports of leptomedusans relative to those of anthomedusans. Indeed, our data, indicating that A. byersi and A. compacta may be graptolites, corroborate hypotheses that other putative hydroids from the Palaeozoic are hemichordates (Bates and Urbanek ; LoDuca and Kramer ; Maletz ).…”

“…, Voigt ; Scrutton ; Taylor ; Jarms and Voigt ; Taylor and Todd ; McKinney ; Suárez Andrés ), which formed through moulding and casting of hydrozoan tissues by activities of organisms producing mineralized skeletons (Taylor ). In addition to these trends, our review shows that several putative hydroids from the lower Palaeozoic have been interpreted as hemichordates (Table , Bates and Urbanek ; LoDuca and Kramer ; Maletz ).…”

“…(), 6 Chapman (), 7 Chapman and Skeats (), 8 Chapman and Thomas (), 9 Cope (), 10 Decker (), 11 Decker (), 12 Eisenack (), 13 Eisenack (), 14 Eisenack (), 15 Eisenack (), 16 Frykman (), 17 Glinski (), 18 Hall (), 19 Howell (), 20 Hu (), 21 Jarms and Voigt (), 22 Kozłowski (), 23 Kraft et al . (), 24 Laufeld (), 25 LoDuca and Kramer (), 26 Maletz (), 27 McGregor and Narbonne (), 28 McKinney (), 29 Mierzejewski (), 30 Miller and Williams (), 31 Muir et al . (), 32 Muscente and Allmon (), 33 Nitecki and Richardson (), 34 Obut (), 35 Olivero and Aguirre‐Urreta (), 36 Quilty (), 37 Ruedemann (), 38 Sass and Rock (), 39 Schram and Nitecki (), 40 Scrutton (), 41 Sennikov (), 42 Skevington (), 43 Soja et al .…”

Systematics of pterobranchs from the Cambrian Period Burgess Shales of Canada and the early evolution of graptolites

“…The graptolites from the Duchesnay Unit in Miller Pass belong to a higher zone than those from the Walcott Quarry; however, both are similar in terms of fossil occurrences and strata positions (Johnston et al 2009). The specimens somewhat resemble the species Archaeolafoea monegettae, which was reported from the Wheeler Shale by LoDuca & Kramer (2014); same is the case of Yuknessia that is found in both British Columbia and Utah. The similarities are mainly in the uppermost part of the colony where autothecal branching patterns are comparable.…”

Graptolite (Hemichordata,Pterobranchia) preservation and identification in theCambrianSeries 3

“…Erect taxa with aperturally widening, conical thecae previously referred to the genus are here excluded. Thus, for example, the species described as Archaeolafoea monegettae (Chapman, ) by LoDuca and Kramer () from the Wheeler Shale of Utah, North America, may better be referred to a different dithecoid graptolite genus, as it shows an erect tubarium with long, distinctly widening thecal tubes. The tubarium shape of Archaeolafoea is similar to that of Rhabdopleura normani with a creeping main strand and lateral, erect, parallel‐sided tubes with straight apertures.…”