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1

The Late Devonian trematid lingulate brachiopod Schizobolus from Poland

100%

Balinski A. , Holmer L. E.

Acta Palaeontologica Polonica

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1999

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tom 44

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nr 3

335-346

EN

A new species of the poorly known lingulate brachiopod Schizobolus is described from the Famennian (Upper Devonian) of Poland. S. polonicus sp. n. has a triangular pedicle notch and a small listrium, indicating that it belongs to the Trematidae within the superfamily Discinoidea. S. polonicus retains some linguloid features, such as a linguloid-like 'pedicle groove' and a V-shaped imprint of the pedicle nerve. The disturbance band, which occurs in the apical part of the larval shell, probably delimits two stages of growth, namely pre-larval (embryonic?) and larval, or, early-larval and late-larval. S. polonicus is the youngest member of the genus, and of the family Trematidae. Five incompletely preserved discinids from the Famennian of Łagów are described as Trematidae gen. et sp. indet.

PL

Bezzawiasowy ramienionóg Schizobolus jest niedostatecznie znanym rodzajem głównie ze względu na zły stan zachowania typowego gaunku S. concentricus z środkowego dewonu Tennessee (USA). Opisane w niniejszej pracy okazy z famenu (górny dewon) Dębnika (region krakowski) i Jabłonnej (Góry Świętokrzyskie) zostały zaliczone do nowego gatunku Schizobolus polonicus sp. n. Gatunek ten charakteryzuje trójkątne wycięcie na nóżkę w skorupce brzusznej, które jest częściowo zakryte słabo zachowującą się, delikatną płytką (listrium). U S. polonicus występuje też - charakterystyczny dla linguloidów - rowek nóżkowy oraz V-kształtny odcisk nerwu nóżkowego w skorupce brzusznej. Okazy z Polski charakteryzuje ponadto występowanie dobrze wykształconego stadium larwalnego muszli. Jest on nieco poprzecznie owalny w zarysie i osiąga przeciętnie 0,42 mm długości. Muszla larwalna jest wyraźnie wyodrębniona z tyłu i z boków, natomiast w części przedniej oddziela ją od reszty muszli jedynie silniej zaznaczona linia przyrostowa. Z zewnątrz muszla larwalna pokryta jest delikatnymi koncentrycznymi liniami przyrostowymi, choć w wyjątkowych przypadkach zachowuje się również odcisk struktury periostrakum (Fig. 3M, N). W części apikalnej muszli larwalnej daje się zaobserwować występowanie koncentrycznego pierścienia przyrostowego (zaburzenie wzrostowe), które wyodrębnia w rezultacie najwcześniejsze stadium wzrostowe muszli. Ten region muszli larwalnej osiąga 0,15-0,20 mm szerokości. Świadczy on, że w rozwoju ontogenetycznym dewońskich trematidów występowało zróżnicowanie na stadium wczesno- i późnolarwalne, lub też na stadium emrionalne (protegulum) i larwalne (u współczesnych dyscinidów takie zróżnicowanie w obrębie muszli larwalnej nie wystepuje). Z famenu Łagowa opisano też pięć silnie ornamentowanych koncentrycznie skorupek reprezentujących zapewne nowy rodzaj z rodziny Trematidae; zbyt skąpy materiał nie pozwala jednak na pełne zdefiniowanie taksonomiczne tej formy.

2

The Early Cambrian [Botomian] stem group brachiopod Mickwitzia from Northeast Greenland

100%

Skovsted C. B. , Holmer L. E.

Acta Palaeontologica Polonica

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2003

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tom 48

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nr 1

EN

The problematic brachiopod Mickwitzia Schmidt, 1888 is re−described based on new material of M. cf. occidens Walcott, 1908 from the Early Cambrian (Botomian) Bastion and Ella Island formations of Northeast Greenland. Etched material demonstrates that Mickwitzia has a lingulid−like juvenile (“larval”) shell with trails of nick−points, reflecting the movement of marginal setae. Juvenile and early mature ventral valves have a lingulid−like pseudointerarea with a pedicle groove. The shell of M. cf. occidens is only partially phosphatic, in particular around the juvenile–early mature shell in both valves. The phosphatic shell includes at least two types of cylindrical structures: (1) slender columns identical with the columns of acrotretoid brachiopods and (2) relatively thicker tubes which may be open to the exterior surface and have internal striations (on the ventral pseudointerarea). The striations are most likely imprints of microvilli and these tubes can be inferred to have contained setae. The thinner linguliform columns and thicker setigerous striated tubes are considered to be homologous with identical structures in the sellate and mitral sclerites of the problematic Micrina, which has been identified as a probable primitive stem group of the Brachiopoda. Mickwitzia represents a more derived member of the stem group Brachiopoda.

3

Lingulate brachiopods from Lower Ordovician [Tremadoc] chalcedonites, Holy Cross Mountains, Poland

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Holmer L. E. , Biernat G.

Acta Palaeontologica Polonica

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2002

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tom 47

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nr 1

EN

Lingulate brachiopods from chalcedonites of Tremadoc age are redescribed based on new material from the Holy Cross Mountains, Poland. The fauna includes 18 species, of which Elliptoglossa polonica and Siphonotretella popovi are new. The enigmatic Orbiculoidea? subovalis Biernat is redescribed as a species of the recently erected aberrant paterulids Diencobolus Holmer, Popov, Koneva, and Bassett. The fauna includes also Acrotreta dissimilis (Biernat), ?Ditreta dividua Biernat, Semitreta maior Biernat, Eurytreta minor Biernat, Mamatia retracta (Popov), Orbithele ceratopygarum (Brøgger), Siphonobolus uralensis (Lermontova), Alichovia analogica Biernat, Pomeraniotreta sp., Akmolina sp., Rowellella sp., Acanthambonia sp. A, Acanthambonia? sp. B, Leptembolon cf. lingulaeformis (Mickwitz), and the earliest known species of Eoconulus. Most of the recorded lingulate species are endemic, but a significant number are now known also from eastern Kazakhstan and the South Urals, as well as from the Tremadoc of Sweden and Norway.

4

The problematic early Cambrian fossil Tumulduria incomperta represents the detached ventral interarea of a paterinid brachiopod

80%

Skovsted C. B. , Kouchinsky A. , Bengtson S. , Holmer L. E.

Acta Palaeontologica Polonica

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2014

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tom 59

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nr 2

EN

The organophosphatic early Cambrian (Terreneuvian, Cambrian Stage 2) fossil Tumulduria incomperta has been problematic ever since its original description in 1969. Comparison of abundant specimens from the Lower Cambrian of Siberia with co-occurring brachiopod valves show that T. incomperta represents the central portion of the ventral interarea of a paterinid brachiopod similar to Cryptotreta neguertchenensis, and that the domed central portion of typical Tumulduria specimens represents the ridge-like pseudodeltidium of the interarea.

5

The new stem-group brachiopod Oymurania from the lower Cambrian of Siberia

80%

Kouchinsky A. , Holmer L. E. , Steiner M. , Ushatinskaya G. T.

Acta Palaeontologica Polonica

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2015

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tom 60

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nr 4

EN

A stem-group brachiopod, Oymurania gravestocki Ushatinskaya gen. et sp. nov. is described herein from the middle Atdabanian-lower Botoman Stages (-Cambrian Stage 3) of the Siberian Platform. The fossils were extracted from limestone beds of the Emyaksin, Perekhod, and Pestrotsvet formations as assemblages of disarticulated orthoconic to cyrtoconic porous shells in apatite preservation. The originally organophosphatic shells of Oymurania are externally similar to mitral sclerites (ventral valves) of the stem-group brachiopod Micrina, although no sellate-like sclerites, nor differentiated subapical area with apophyses were recognised in our material. The range of Oymurania shells with sub-central to posteromarginal apex is similar to that of ventral valves ofMickwitzia. Oymurania is also characterised by the system of radial and orthogonal canals open in pairs or triplets in small depressions or indentations of growth lamellae in the outer shell surface. The orthogonal (Micrina-Setatella type) and radial (horizontal setigerous tubes) canals are widespread among the early Cambrian stem-group brachiopods, such as Micrina, Mickwitzia, and Setatella. In addition to these canals, Oymurania exhibits a well-developed acrotretoid columnar microstructure, also known from Setatella. A broad subapical platform in cyrtoconic shells (presumably ventral valves) of Oymurania is interpreted homologous to the deltoid area in mitrals of Micrina and pseudointerarea/interarea in ventral valves of Setatella/paterinid brachiopods. Except with probable cell imprints and openings of orthogonal canals, no morphological differentiation was, however, reflected by the shell interior of Oymurania gravestocki. Being closely related to tannuolinids and mickwitziids, Oymurania complements the picture of diversification of the early Cambrian stem-group brachiopods that occurred in parallel with radiation of paterinids and other crow-group brachiopods on the Siberian Platform and worldwide.

6

Soft-part preservation in a linguliform brachiopod from the lower Cambrian Wulongqing Formation [Guanshan fauna] of Yunnan, South China

80%

Hu S. , Zhang Z. , Holmer L. E. , Skovsted C. B.

Acta Palaeontologica Polonica

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2010

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tom 55

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nr 3

495-505

EN

Linguliform brachiopods were important components of early Cambrian benthic communities. However, exceptionally preserved soft parts in Cambrian linguliform brachiopods are extremely sparse, and the most important findings are from the early Cambrian Chengjiang Konservat Lagerstätte of Kunming, southern China. Here we describe the first record of preserved soft−part anatomy in a linguliform brachiopod from the early Cambrian Guanshan fauna (Wulongqing Formation, Palaeolenus Zone); a unit which is considerably younger than the Chengjiang fauna. The well preserved soft anatomy include linguliform pedicles, marginal setae and, in a few cases, an intact lophophore imprint. The pedicle has pronounced surface annulations, with its proximal−most part enclosing the apex of the ventral pseudointerarea; the pedicle is up to 51 mm long, corresponding to more than 4 times the sagittal length of the shell, and 12% of the maximum valve width. In details of their preservation, these new fossils exhibit striking similarities with the linguliforms from the older Chengjiang fauna, and all specimens are preserved in a compressed state as flattened impressions. The new linguliform has an elongate oval to subtriangular shell and an elongate triangular ventral pseudointerarea; the pedicle emerged from an apical foramen through a poorly preserved internal pedicle tube. The new linguliform is most similar to the mostly organic−shelled siphonotretoid−like brachiopod Acanthotretella spinosa, recently described from the classic middle Cambrian Burgess Shale Konservat Lagerstätte, British Columbia, Canada. The new species Acanthotretella decaius sp. nov. is described; it differs from A. spinosa in having a slightly thicker pedicle, and a larger and more rigid, probably partly mineralised shell, indicating that the mostly organic shell of A. spinosa may represent a secondary reduction of shell mineralisation. However, the spine−like setae of the new species are unfortunately poorly preserved only at the margin of the shell, but the new species is referred tentatively to the Superfamily Siphonotretoidea. The occurrence of A. decaius in the Guanshan fauna is the first lower Cambrian (Series 2, early Stage 4) record of both Acanthotretella and siphonotretoids, and it represents the first description of a lophophore and digestive tract from the siphonotretoid lineage.

7

Middle Cambrian lingulate brachiopods from the Tarbagatay Range, Kazakhstan

80%

Popov L. E. , Holmer L. E. , Gorjansky V. J.

Acta Palaeontologica Polonica

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1996

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tom 41

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nr 3

EN

Early Middle Cambrian (Amgian) lingulate brachiopods from the Tarbagatay Range in eastern Kazakhstan represent mostly endemic taxa, which may suggest that the Tarbagatay Range was relatively isolated from adjacent terranes during that time; only Kleithriatreta indicate similarity with the Australian part of Gondwana, as well as with the south and central Kazakhstanian terranes. Late Middle Cambrian (Mayan) taxa from the same area are mostly cosmopolitan. Kostjubella relaxata gen. et sp. n., Prototreta (?) dolosa sp. n. and Stilpnotreta galinae sp. n. are proposed.

8

Review of the Ordovician stratigraphy and fauna of the Anarak Region in Central Iran

61%

Popov L. E. , Hairapetian V. , Evans D. H. , Ghobadi Pour M. , Holmer L. E. , Baars C.

Acta Geologica Polonica

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2015

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tom Vol. 65, no. 4

403--435

EN

The Ordovician sedimentary succession of the Pol-e Khavand area, situated on the northern margin of the Yazd block, has important differences from those in other parts of Central Iran. It has been established that the presumably terminal Cambrian to Lower Ordovician volcano-sedimentary Polekhavand Formation, exposed in the Pol-e Khavand area, has non-conformable contact with greenschists of the Doshakh Metamorphic Complex. The succeeding, mainly siliciclastic Chahgonbad Formation contains low to moderately diverse faunal assemblages, including brachiopods, cephalopods, trilobites and tentaculitids. The Darriwilian age of the lower part of the formation is well established by the co-occurrence of brachiopod genera Camerella, Phragmorthis, Tritoechia and Yangtzeella. The associated rich cephalopod fauna is different from the Darriwilian cephalopod associations of the Alborz terrane and may show some affinity with warm water faunas of North China and South Korea. It is likely that the Mid Ordovician fauna recovered from the lower part of the Chahgonbad Formation settled in the area sometime during a warming episode in the late Darriwilian. By contrast the low diversity mid Katian brachiopod association includes only three taxa, which occur together with the trilobite Vietnamia cf. teichmulleri and abundant, but poorly preserved tentaculitids questionably assigned to the genus Costatulites. This faunal association bears clear signatures linking it to the contemporaneous cold water faunas of the Arabian, Mediterranean and North African segments of Gondwana. Four brachiopod species recovered from the Chahgonbad Formation, including Hibernodonta lakhensis, Hindella prima, Lomatorthis? multilamellosa and Yangtzeella chupananica are new to science.

9

Camenellan tommotiids from the Cambrian Series 2 of East Antarctica: Biostratigraphy, palaeobiogeography, and systematics

61%

Claybourn T. M. , Skovsted C. B. , Betts M. J. , Holmer L. E. , Bassett-Butt L. , Brock G. A.

Acta Palaeontologica Polonica

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2021

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tom 66

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nr 1

10

The oldest brachiopods from the lower Cambrian of South Australia

51%

Topper T. P. , Holmer L. E. , Skovsted C. B. , Brock G. A. , Balthasar U. , Larsson C. M. , Stolk S. P. , Harper D. A. T.

Acta Palaeontologica Polonica

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2013

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tom 58

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nr 1

EN

The morphology and organophosphatic shell structure of the paterinate brachiopod Askepasma is documented using new and previously collected specimens from the lower Cambrian of South Australia. Lack of adequately preserved material has seen the majority of paterinate specimens previously reported from South Australia referred to the genus Askepasma and treated under open nomenclature. Large collections of paterinates from the lower Cambrian Wilkawillina, Ajax, and Wirrapowie limestones in the Arrowie Basin, South Australia have prompted redescription of the type species Askepasma toddense and the erection of a new species, Askepasma saproconcha sp. nov. Askepasma saproconcha sp. nov. currently represents the oldest known brachiopod from the lower Cambrian successions in South Australia with a FAD in pre−trilo− bitic (Terreneuvian, Cambrian Stage 2, lower Atdabanian) strata in the basal part of the Wilkawillina and Wirrapowie limestones. Askepasma toddense predominantly occurs in Abadiella huoi Zone equivalent strata (Unnamed Cambrian Se− ries 2, Stage 3, middle–upper Atdabanian) in the upper part of the lower Wilkawillina, Wirrapowie, and Ajax limestones. The shell microstructure of Askepasma suggests a proximal stem group position within the Brachiopoda and similarities with tommotiid taxa provides further evidence that the ancestry of crown group brachiopods is firmly entrenched within the Tommotiida.

11

Early–middle Cambrian stratigraphy and faunas from northern Siberia

41%

Kouchinsky A. , Alexander R. , Bengtson S. , Bowyer F. , Clausen S. , Holmer L. E. , Kolesnikov K. A. , Korovnikov I. V. , Pavlov V. , Skovsted C. B. , Ushatinskaya G. , Wood R. , Zhuravlev A. Y.

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tom 67

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nr 2