Lars E Holmer

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Verified

Lars verified their affiliation via an institutional email.

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• PhD
• Professor at Uppsala University

Ordovician (Darriwilian to Sandbian) micromorphic linguliform lingulate brachiopods are described from the Guniutan Formation at the Fenxiang section in Hubei province, and the Maocaopu and Cili sections in Hunan province of south-central China, situated on the Yangtze Platform. A total of 7560 specimens from 155 limestone samples (within the inter...

A characteristic coarsely pitted ornamentation (with pits larger than 0.015 mm across) can be found on some very enigmatic and rare Lower Ordovician phosphatic-shelled linguliform brachiopods, including the paterinid Lacunites balaschovae Gorjansky and the obolid Foveola maarduensis Gorjansky. Both of these species are poorly understood and known f...

A synoptic analysis of previously published material and new finds reveals that Himalayan Cambrian brachiopods can be referred to 18 genera, of which 17 are considered herein. These contain 20 taxa assigned to species, of which five are new: Eohadrotreta haydeni, Aphelotreta khemangarensis, Hadrotreta timchristiorum, Prototreta? sumnaensis and Amic...

One of the first phyla to acquire biomineralized skeletal elements in the Cambrian, brachiopods represent a vital component in unraveling the early evolution and relationships of the Lophotrochozoa. Critical to improving our understanding of lophotrochozoans is the origin, evolution and function of unbiomineralized morphological features, in partic...

Ecological interactions, including symbiotic associations such as mutualism, parasitism and commensalism are crucial factors in generating evolutionary novelties and strategies. Direct examples of species interactions in the fossil record generally involve organisms attached to sessile organisms in an epibiont or macroboring relationship. Here we p...

Three exceptionally preserved, silicified and articulated complete shells with pedicles of kutorginate brachiopods are described from the Cambrian Burj Formation (latest Stage 4) of Jordan. One specimen can be assigned to Trematosia radifer (Cooper) and the others represent a new unnamed species of Kutorgina. The silicified pedicles differ signific...

Four craniopside species of Pseudopholidops from the East Baltic and Iran, including P. ingriana sp. nov., are described. Pseudopholidops is the earliest yet documented craniopside, first appearing in the upper Darriwilian of Estonia. Like other craniiforms, Pseudopholidops has a lecithotrophic larval stage, settling on the ventral side of the body...

Cambrian Lagerstätten yield exceptionally preserved fossils that have greatly improved our understanding of the origin and evolution of animal groups. Brachiopoda, a phylum of bivalved marine invertebrates nested firmly within the lophotrochozoan protostomes, are widely recovered in such Lagerstätten. The marginal chitinous setae (or chaetae) of br...

The post-impact fauna of the Dalby Limestone of Tvären Bay has been extensively examined, with the exception of the Palaeostomate bryozoan taxa present. Here, we report three palaeostomate bryozoans found in limestone boulders recovered from glacial deposits on Ringsö Island derived from Tvären Bay, Sweden. The bryozoan fauna includes Pachydictya b...

One of the most complete, spectacular and most thoroughly documented sections of Ordovician cool to temperate water limestones, globally. It is significant in understanding the Ordovician world.

Biologically-controlled mineralization producing organic-inorganic composites (hard skeletons) by metazoan biomineralizers has been an evolutionary innovation since the earliest Cambrian. Among them, linguliform brachiopods are one of the key invertebrates that secrete calcium phosphate minerals to build their shells. One of the most distinct shell...

Biologically-controlled mineralization producing organic-inorganic composites (hard skeletons) by metazoan biomineralizers has been an evolutionary innovation since the earliest Cambrian. Among them, linguliform brachiopods are one of the key invertebrates that secrete calcium phosphate minerals to build their shells. One of the most distinct shell...

Biologically-controlled mineralization producing organic-inorganic composites (hard skeletons) by metazoan biomineralizers has been an evolutionary innovation since the earliest Cambrian. Among them, linguliform brachiopods are one of the key invertebrates that secrete calcium phosphate minerals to build their shells. One of the most distinct shell...

Brachiopods first appeared in the early Cambrian and persist till present. They are one of the main lineages of marine invertebrates that diversified throughout the Paleozoic and reached their maximum diversity of high-rank taxonomy during the Ordovician. During this time interval, brachiopods were mainly dominated by the articulated Orthida and St...

Stop 2. Tomten quarry

Stop 5. Hällekis quarry

Biologically-controlled mineralization producing organic-inorganic composites (hard skeletons) by metazoan biomineralizers has been an evolutionary innovation since the earliest Cambrian. Among them, linguliform brachiopods are one of the key invertebrates that secrete calcium phosphate minerals to build their skeletons. One of the most distinct sh...

There are few studies using the synchronous analysis of organophosphatic small shelly fossils (SSFs), despite their potential importance for understanding the Cambrian explosion. The nature of organic biopolymers in the shells of many SSFs is still unknown. Here, shell matrices in SSFs within lower Cambrian carbonate strata across the Arrowie Basin...

This is to illustrate the vascular system in a ventral mantle of the early Cambrian lingulate brachiopod Diandongia pista from the Chengjiang Fauna. As you see, the mantle canal system is more complicated than the baculate or bifurcate condition described earlier in the other lingulates.

Biologically controlled mineral crystals producing organic-inorganic composites (hard skeletons) by metazoan biomineralizers has been an evolutionary innovation for more than half billion years on Earth. Among them, linguliform brachiopods are the only invertebrates that secrete phosphate to build their skeletons. One of the most distinct shell str...

Biologically controlled mineral crystals producing organic-inorganic composites (hard skeletons) by metazoan biomineralizers has been an evolutionary innovation for more than half billion years on Earth. Among them, linguliform brachiopods are the only invertebrates that secrete phosphate to build their skeletons. One of the most distinct shell str...

Biological activity was the major triggering factor driving Earth's organic and inorganic cycles across the biosphere, lithosphere, and atmosphere. A key question in the evolution of Earth's ecosystem is when and how different animals emerged and flourished and how their appearance impacted the hydrosphere-atmosphere-lithosphere cycles. The Cambria...

Schizambon is one of the earliest and most distinctive genera in the Order Siphonotretida. However, current knowledge of siphonotretide phylogeny and early evolution requires understanding of their earliest ontogeny. In this study, the new species Schizambon tongziensis from the Tungtzu Formation at Honghuayuan section in Guizhou Province, South Ch...

Simple Summary Small skeletal fossils are reported for the first time from the early Cambrian Guojiaba Formation, southern Shaanxi, China. All specimens were recovered from bioclastic limestone interbeds and encompass a wide variety of skeletal clades, including brachiopods, sphenothallids, archaeocyaths, bradoriids, sponge spicules, echinoderm pla...

A steinkern of an endoceratid nautiloid siphuncle contains a Trypanites sozialis boring with a lingulate brachiopod Rowellella sp. shell inside. The steinkern of this endoceratid formed during early lithification of the sediment on the seafloor. The lithified steinkern of this siphuncle was either initially partially exposed to the seawater or was...

Biologically controlled mineral crystals producing organic-inorganic composites (hard skeletons) by metazoan biomineralizers has been an evolutionary innovation for more than half billion years on Earth. Among them, linguliform brachiopods are the only invertebrates that secrete phosphate to build their skeletons. One of the most distinct shell str...

The Ordos Basin is located in the western part of the North China Platform and is the second largest sedimentary basin in China; the basin has a huge thickness of the Early Palaeozoic marine deposits, especially the Ordovician ones. The Zhaolaoyu Formation is distributed in the Fuping area of the southern Ordos Basin, where brachiopods, gastropods,...

The evolution of brachiopod symbiosis is closely tied to the evolution of brachiopod faunas and their partner groups during the early Palaeozoic. Brachiopod groups with a larger number of taxa had more symbiotic associations, and there was no specific group that was more prone to symbiosis during this time interval. The first symbiotic associations...

Morphology usually serves as an effective proxy for functional ecology,1–5 and evaluating morphological, anatomical, and ecological changes permits a deeper understanding of the nature of diversification and macroevolution.5–12 Lingulid (order Lingulida) brachiopods are both diverse and abundant during the early Palaeozoic but decrease in diversity...

Endobiotic cornulitids formed symbiotic associations with tabulate corals and stromatoporoids in the Katian (Late Ordovician) of Estonia. The cornulitids benefited from a stable substrate and additional protection against predators offered by the skeleton of their hosts. Symbiotic lingulates and Chaetosalpinx-like bioclaustration structures are her...

Diandongia pista Rong is the thickest-shelled and strongly mineralized of all the brachiopods that have been recorded from the Chengjiang Fauna. It is also one of the most common species in the biota. Previous accounts have concentrated largely on the exceptionally preserved soft-bodied anatomy of this species. Here its detailed internal and extern...

The Ediacaran–Cambrian transition, one of the major turning points in Earth’s history, is characterized by an epoch-making change in biosphere. In South China, the late Ediacaran Dengying Formation (ca. 551–538 Ma) is an important stratigraphic unit yielding trace fossils, tubular skeletal fossils and some complex forms that represent possible bila...

Supplementary online material for Early–middle Cambrian stratigraphy and faunas from northern Siberia

New assemblages of skeletal fossils chemically extracted from carbonates of the Cambrian Stage 2–Drumian Stage are reported from the lower reaches of the Lena River as well as from the Khorbusuonka, Malaya Kuonamka, and Bol’shaya Kuonamka rivers in northern part of the Siberian Platform. The fauna studied with scanning electron microscopy includes...

The Cambrian successions at the Chihuarruita Hill outcrop, Sonora, Mexico, have yielded two successive linguliform brachiopod assemblages that are transitional between Cambrian Stage 4 and the newly recognized global Wuliuan Stage. The lowermost assemblage includes Dictyonina sp., Paterina sp., Eothele sp., Hadrotreta rara ? (Cooper), and Linnarsso...

New assemblages of skeletal fossils chemically extracted from carbonates of the Cambrian Stage 2–Drumian Stage are reported from the lower reaches of the Lena River as well as from the Khorbusuonka, Malaya Kuonamka, and Bol’shaya Kuonamka rivers in northern part of the Siberian Platform. The fauna studied with scanning electron microscopy includes...

Two massive precipitation events of polymetallic ore deposits, encrusted by a mixture of authigenic carbonates, are documented from the Cambrian of the semi-enclosed Baltoscandian Basin. δ34S (‒9.33 to ‒2.08‰) and δ33S (‒4.75 to ‒1.06‰) values from the basal sulphide breccias, sourced from contemporaneous Pb–Zn–Fe-bearing vein stockworks, refect su...

Phosphate-shelled brachiopods differ in filter-feeding lifestyle, with Lingula anatina an active infaunal burrower, and Discinisca tenuis a shallow marine epibenthic animal. The shells of these animals are built of organophosphatic constituents, the organic fibres/sheets reinforced with calcium phosphate to provide a sophisticated ultrastructural r...

Small Shelly Fossils (SSFs) from the Cambrian are widely distributed and well known across different paleocontinents of the world. However, middle Cambrian SSFs from North China Platform have only rarely been documented until now. In this paper, we presented the first report on SSFs from bioclastic and oolitic limestones of the Zhangxia and Hsuzhua...

A moderately diverse assemblage of brachiopods from the Latham Shale Lagerstätte (Cambrian Series 2, upper Stage 4) and the upper Cadiz Formation (Miaolingian, Wuliuan), California is described in detail for the first time. The fauna includes both linguliform and rhynchonelliform brachiopods-Hadrotreta primaea (Walcott, 1902), Paterina prospectensi...

The identification of brachiopods requires specialist knowledge held by a limited number of researchers and is very time-consuming. The new technique of deep learning by artificial intelligence offers promising tools to break these shackles to develop computer automatic identification. However, we found that the traditional convolution neural netwo...

Laser micropyrolysis gas chromatography-mass spectrometry enables researchers to selectively obtain chemical information about the organic matter in specific parts of a variety of specimens, such as coals and fossils, in order to elucidate chemical composition. This paper briefly reviews the history of this type of pyrolysis and examines whether th...

Acrotretides are extinct micromorphic bra-chiopods that exhibited considerable morphological variation during their rapid evolution in the early Palaeozoic. The plano-conical shells of acrotretides are distinct in comparison to other brachiopod groups and despite their diversity and abundance in early Palaeozoic communities, their origins, early ev...

The Silurian (Aeronian) post-extinction recovery brachiopod fauna of Iran and Afghanistan is characterized by a proliferation of the Stegocornu Brachiopod Association, which includes prominent endemic rhynchonellide and spiriferide components. A local variety of that association, recently recovered from the Shabdjereh Formation of Kerman Province,...

Cambrian Series 2 shelly fossils from thick carbonate successions in East Antarctica have received limited systematic treatment through the 20th century. Described here are the East Antarctic camenellan tommotiids from the Shackleton Limestone in the Central Transantarctic Mountains and the Schneider Hills limestone in the Argentina Range. This mat...

Diverse and abundant fossil taxa have been described in the lower Cambrian Shipai Formation in the Three Gorges area of Hubei Province, South China, but the taxonomy and diversity of the co-occurring brachiopod fauna are still far from clear. Here we describe the brachiopod fauna recovered from the Shipai Formation in the Three Gorges area of South...

Rare Oichnus simplex drill holes occur in mature obolid shells from the Cambrian/Ordovician boundary beds of northern Estonia (Iru and Ülgase) and the uppermost Cambrian of NW Russia (Lava River). The drill holes are significantly more common in the central rather than the marginal regions of the obolid valves. Drilling predators attacked Ungula in...

Recent excavations of the Guanshan biota at the Shijiangjun section in the eastern Yunnan Province, South China, have revealed many well-defined faecal pellets and related trace fossils. These can be assigned to three morphotypes, which have affinities with the ichnogenera Tomaculum, Alcyonidiopsis and Tubulichnium. Morphotype 1 is an unbranched bu...

Phosphate-shelled brachiopods differ in filter-feeding lifestyle, with Lingula anatina an active infaunal burrower, and Discinisca tenuis a shallow marine epibenthic animal. The shells of these biomineralized organisms are built of organophosphatic constituents, the organic fibres/sheets reinforced with calcium phosphate (Ca-phosphate) to provide a...

The shells of linguloid brachiopods such as Lingula and Discinisca are inorganic-organic nanocomposites with a mineral phase of calcium phosphate (Ca-phosphate). Collagen, the main extracellular matrix in Ca-phosphatic vertebrate skeletons, has not previously been clearly resolved at the molecular level in organophosphatic brachiopods. Here, modern...

Limestones of the Xihaoping Member of the Dengying Formation in the Xiaoyangba section, South China, yield the oldest known Cambrian brachiopod–trilobite association. In this member, the trilobite Parabadiella cf. huoi co-occurs with the new brachiopod species Eoobolus incipiens sp. nov. The association provides potential for correlation of lower C...

Brachiopod shell accumulations are abundant and diverse in the lower Cambrian strata of Yunnan Province, South China, but most commonly they are composed of linguloid and acrotheloid brachiopods. Here, we describe the first record of shell beds with high-density accumulations of microscopic acrotretoid brachiopods (usually <2 mm in width) in the mu...

Abstract.—Brachiopod shell accumulations are abundant and diverse in the lower Cambrian strata of Yunnan Province, South China, butmost commonly they are composed of linguloid and acrotheloid brachiopods. Here, we describe the first record of shell beds with high-density accumulations of microscopic acrotretoid brachiopods (usually <2 mm in width)...

Micromorphic acrotretide brachiopods first appeared during Cambrian Epoch 2 and subsequently experienced a rapid diversification. However, our knowledge of acrotretide origins and early evolution is hampered by our poor understanding of their earliest representatives. Here, we describe one of the oldest known acrotretides from the Cambrian Series 2...

New records of the poorly known acrotretid (Biernatidae) microbrachiopod Opsiconidion minor Popov are described from middle Emsian strata of the Ogilvie Formation in east­central Alaska and the adjacent Yukon Territory, Canada, and compared with new better­preserved topotypes from the late Early Devonian (Emsian) of Novaya Zemlya, Russia. In Alas...

In this work, we present the first report of two species of brachiopods, Paterina prospectensis and Mickwitzia occidens, displaying soft part preservation from Lower Cambrian Latham Shale (Series 2, Stage 4), California. The specimen of P. prospectensis is provided with delicate setae preserved as pseudomorphed framboidal pyrite. This observation e...

A moderately diverse assemblage of micromor-phic linguliform brachiopods, including Tapuritreta gri-bovensis sp. nov., Wahwahlingula? pankovensis sp. nov., Acrothele sp., Anabolotreta? sp., Orbithele? sp. and Stilp-notreta sp., is for the first time described from the Cam-brian Karpinsk Formation (Miaolingian, Guzhangian) of the South Island of Nov...

The origin of the Brachiopoda has long been a hotly debated topic, and various models have been proposed following the latest finds of exceptionally preserved material. The lower Cambrian (Stage 3) Heliomedusa orienta from the Chengjiang Konservat‐Lagerstätte, eastern Yunnan of South China, is an important example of exceptional preservation. A wid...

Alunskiffer Den svenska och baltiska alunskiffern har stor utbredning och är kanske en av vår regions mest dagsaktuella och kontroversiella mineralrika natur resurser. Det är förekomsten av vana din och andra mineraliseringar, t.ex. av uran, och den ökande efterfrågan på dessa metaller som gör skiffern intressant. Motståndet mot prospek tering och...

The origin of Cambrian brachiopods and their phylogenetic relationship with other lophotrochozoans is far from clear. Lingulellotretidae, the oldest family of lingulate brachiopods, is typified by possessing a pouch-like coelomic extension beyond the hinge line, subtended in a triangular pseudointerarea. The early Cambrian (Stage 4) linguloid brach...

Brachiopods from Cambrian Series 2, Stage 4 carbonate strata of the Byrd Group in the Central Transantarctic Mountains, East Antarctica, are described for the first time. These include six lingulate, one paterinate and one rhynchonelliform taxon, including the new lingulate brachiopod Plicarmus wildi gen. et sp. nov. The biostratigraphy correlates...

The enigmatic and aberrant lingulate brachiopod Aulonotreta antiquissima (Eichwald) from the Dapingian (Volkhov Stage) Toila Formation of northern Estonia and St Petersburg area (Historical Region of Ingria, Ingermanland, or Inkerinmaa; English, Swedish, Finnish) is re-described together with the new species, Aulonotreta neptuni, from the lower Dar...

Abundant and diverse small shelly fossils have been reported from Cambrian Series 2 in North China, but the co-occurring brachiopods are still poorly known. Herein, we describe seven genera, five species and two undetermined species of organophosphatic brachiopods including one new genus and new species from the lower Cambrian Xinji Formation at Sh...

The origin of the Brachiopoda has long been a hotly debated topic of discussions, and various models have been proposed, both based on molecular studies of their living representatives as well as on morpho-anatomical investigations of fossils with exceptional preservation of soft parts. The lower Cambrian (Stage 3) Heliomedusa orienta from the Chen...

With the increasing emphasis on basic research in China, great achievements have been made in paleontology, especially in the study of early life and the Cambrian explosion. Research facilities have been improved, such as Scanning Electron Microscopy (SEM) and X-ray micro-tomography Scanner (Micro-CT) have been used extensively in researches. Micro...

The Tremadocian (Early Ordovician) is currently considered a time span of greenhouse conditions with tropical water surface temperature estimates, interpolated from oxygen isotopes, approaching 40 °C. In the mid-latitude Baltoscandian Basin, conodonts displaying low δ18O values, which suggest high temperatures (>40 °C) in the water column, are in c...

A comprehensive review and phylogenetic analysis of genera and species presently assigned to the rhyn-chonelliform superfamily Nisusioidea and family Nisusiidae suggests that this short-lived but important group of bra-chiopods first appeared in peri-Gondwana during the second half of the Cambrian Series 2, before going extinct by the end of Drumia...

An assemblage of Cambrian Series 2, Stages 3–4, conchiferan mollusks from the Shackleton Limestone, Transantarctic Mountains, East Antarctica, is formally described and illustrated. The fauna includes one bivalve, one macromollusk, and 10 micromollusks, including the first description of the species Xinjispira simplex Zhou and Xiao, 1984 outside No...

The Tremadocian (Early Ordovician) is currently considered a time span of greenhouse conditions with tropical water surface temperature estimates, interpolated from oxygen isotopes, approaching 40°C. In the high-latitude Baltoscandian Basin, these data are in contrast with the discovery of glendonite, a pseudomorph of ikaite (CaCO3·6H2O) and valuab...

We present the first multiproxy chronostratigraphic assessment of the early-mid Cambrian Byrd Group from the Central Transantarctic Mountains, East Antarctica. This region was sutured to southern Australia throughout the Cambrian and is an integral, but poorly understood, region of East Gondwana. Two in-situ autochthonous stratigraphic sections wer...

Background: Our understanding of the ontogeny of Palaeozoic brachiopods has changed significantly during the last two decades. However, the micromorphic acrotretoids have received relatively little attention, resulting in a poor knowledge of their ontogeny, origin and earliest evolution. The uniquely well preserved early Cambrian fossil records in...

Exceptionally preserved, silicified and articulated complete shells of the rhynchonelliform kutorginate brachiopod Nisusia sulcata are redescribed from the middle Cambrian (Series 3) Marjum Limestone, Utah. Cylindroid sausage-like protrusions, emerging posteriorly between the valves, were originally interpreted as faecal in origin, but restudy unde...

New problematic helcionelloid molluscs from the Shackleton Limestone (Cambrian Series 2, Stage 3-4) outcropping in the Transantarctic Mountains can be reliably identified to the new Dailyatia odyssei Zone of South Australia. Keystone taxa such as the Zone’s eponym, Pojetaia runnegari and Mackinnonia rostrata also allow for increased correlation of...

乳孔贝（acrotretids）是一类繁盛于晚寒武世—奥陶纪并灭绝于泥盆纪的微型腕足动物，其特殊的壳体形态及柱状结构使其与其他舌形贝型腕足动物的系统学关系模糊不清。华南峡东地区早寒武世（第二世）水井沱组薄层灰岩中发现最早的精美保存的乳孔贝类腕足动物Eohadrotreta zhenbaensis（镇巴始强壮贝）。本文首次解析Eohadrotreta的壳体形态和三级壳层结构。通过壳体显微结构的研究，解译出其个体存在的4个壳体发育阶段，即胎壳（protegulum）、幼年壳（brephic shell）、少年壳（neanic shell）和成年壳（mature shell），从而揭示乳孔贝悬浮滤食生活的幼虫阶段及其后的变态发育过程。更重要的是，在对这些壳体化石进行扫描成像过程中还发现精美保存的表...

The kutorginates are commonly the most abundant rhynchonelliform brachiopod found in the early Cambrian; they are also some of the oldest known rhynchonelliforms, first appearing in the Unnamed Series 2 (Atdabanian equivalent) and becoming extinct sometime in Cambrian Series 3 (Amgaian equivalent). Moreover, kutorginates are the first known member...

The earliest growth of post-metamorphic (post-larval) shells in two species of Eohadrotreta is described from the Cambrian Shuijingtuo Formation of South China. Two different growth patterns can be observed by quantifying developmental variations in size and shape of successive stages of post-metamorphic shell growth (including the pedicle foramen...