Steffen Kiel

• PhD
• Senior Researcher at Swedish Museum of Natural History

The origin and evolution of the faunas inhabiting deep-sea hydrothermal vents and methane seeps have been debated for decades. These faunas rely on a local source of sulfide and other reduced chemicals for nutrition, which spawned the hypothesis that their evolutionary history is independent from that of photosynthesis-based food chains and instead...

Aim Nautilus and Allonautilus , last members of the once widespread nautiloid cephalopods, are today restricted to the deep central Indo‐West Pacific Ocean, for reasons that remain unclear. Cephalopod evolution is generally considered as being driven by vertebrate predation; therefore, we investigated the role of whales and seals in the decline of...

The Humboldt Current System along the Pacific coast of South America creates one of the most productive ecosystems on Earth. To trace the origin of the water masses in this area, we measured neodymium isotope compositions (ԑNd) in tooth enameloid of two genera of coastal sharks from latest Oligocene to early Pleistocene strata in the Pisco and Saca...

Kelp forests are highly productive and economically important ecosystems worldwide, especially in the North Pacific Ocean. However, current hypotheses for their evolutionary origins are reliant on a scant fossil record. Here, we report fossil hapteral kelp holdfasts from western Washington State, USA, indicating that kelp has existed in the northea...

Reconstructing the tree of life and understanding the relationships of taxa are core questions in evolutionary and systematic biology. The main advances in this field in the last decades were derived from molecular phylogenetics; however, for most species, molecular data are not available. Here, we explore the applicability of two deep learning met...

Fossil egg capsules of chimaeroids (holocephalian fishes), although rare, have been known for more than 150 years (Bessels, 1869; Meunier, 1891a) and have been found in rocks as old as Upper Triassic (Gottfried and Fordyce, 2014). Egg capsules of extant chimaeroids are spindle shaped, with a smooth central body where the embryo develops, an elongat...

The calyptraphorine stromboid, Aulacodiscus lissoni (Douvillé, 1921), found in northern Peru in bioclastic sandstones of the lower Eocene Basal Salina Formation, is notable for its complete envelopment by calluses, including massive left-lateral callus knobs. Previous shell descriptions suffered from the absence of the anterior end. Newly reported...

Abundant shark and rare actinopterygian teeth are reported from a locality within the early Eocene (Ypresian) lower part of the Crescent Formation exposed in the Hamma Hamma River valley on the eastern Olympic Peninsula, Washington State, USA. This part of the Crescent Formation is predominantly submarine volcanic basalt with some sedimentary inter...

We report a newly discovered hydrocarbon seep deposit from the Eocene bathyal flysch, exposed in the town of Buje in Istria, Croatia. Molecular fossils of methane‐oxidizing prokaryotes and abundant banded botryoidal cements indicate strong fluid flux at this site. We systematically describe the fauna of this and another seep deposit previously repo...

The feeding habits and predation behaviour of organisms can exert significant control on the dynamics of local food webs. Yet, little is known about the effects of predation on the material and trophic transfer dynamics in chemosynthesis-based ecosystems. Here, we investigated the rare earth element (REE) composition of soft tissues and hardparts f...

Here, we report on 33 molluscan species from Miocene ’Calcari a Lucina’ hydrocarbon-seep deposits in northern Italy. Three new species are described: the chilodontaid gastropod Putzeysia diversii sp. nov., the lucinid bivalve Miltha (sensu lato) romaniae sp. nov., and Sisonia ultimoi sp. nov., a heterodont bivalve of uncertain taxonomic affinity. F...

Reduced compounds dissolved in seeping fluids, such as methane and hydrogen sulfide, are the main energy sources in submarine cold seep systems, where they nourish the unique chemosynthesis-based ecosystems. Chemosymbi-otic bivalves are the dominant macrofauna in many of these ecosystems and have been extensively studied due to their large biomass...

New discoveries of Cenozoic deep-water hydrocarbon seep deposits and continued collecting at previously documented sites in the North Pacific region have resulted in additional fossils of vesicomyid bivalves and necessitate a systematic review. We report five new vesicomyid species, including four species from western Washington State, USA: Isorrop...

Loose limestone blocks of a newly recognized hydrocarbon-seep deposit from the lower Oligocene Jansen Creek Member of the Makah Formation were collected on a beach terrace close to the mouth of Bullman Creek in Washington State, USA. The limestone consists largely of authigenic carbonate phases, including 13 C-depleted fibrous cement forming banded...

Ancient hydrocarbon-seep sites known as "Calcari a Lucina" are common in Miocene strata of northern Italy and typically consist of carbonate deposits dominated by large luci-nid, bathymodiolin, and vesicomyid bivalves. Here we report two new sites found in Upper Miocene strata at Monte Mauro near Brisighella in the Emilia-Romagna province. One is u...

The Miocene Tagay section in the north-western part of Olkhon Island, Lake Baikal, provides a unique window into past life in northern Asia. To aid palaeoenvironmental reconstructions, we carried out whole-rock geochemical analyses of 17 sedimentary layers of this section. The aim of this geochemical approach is to examine the element variations as...

Mussels in the subfamily Bathymodiolinae are common inhabitants of deep-sea chemosynthetic habitats, but in many places their diversity remains unknown. Here we describe Nypamodiolus samadiae n. gen. et n. sp. (Mytilidae: Bathymodiolinae) based on samples collected from the Haima cold seep in the South China Sea. Phylogenetic analyses based on frag...

We report 35 molluscan species from Late Miocene cold-seep carbonates from the Amlang Formation in the Ilocos�Central Luzon Basin in Luzon Island, Philippines, collected in a large quarry in the province of Pangasinan. The 19 bivalve species are largely representatives of chemosymbiotic families; the six new species are the nuculid Acila (Truncaci...

We describe a new genus of the chemosymbiotic bivalve family Vesicomyidae, Squiresica, for two Oligocene species, previously assigned to Archivesica, from western North America. Squiresica is characterized by a small and weakly inflated shell, a small to nearly absent pallial sinus, an Archivesica-like hinge dentition, with an indistinct to well in...

Bivalves are an important part of the methane seep fauna ever since seeps appeared in the geologic record. The chronostratigraphic ranges of seep-inhabiting chemosymbiotic bivalves show an overall increase in diversity at seeps since the Paleozoic. The most common group at Paleozoic and early Mesozoic seeps are modiomorphids, with a few additional...

The natural dynamics of fluid flow at methane seeps and increasingly human activities influence the biogeochemistry of the microenvironment and further determine the activity of the chemosynthetic communities within these ecosystems. However, ways to reconstruct short-term fluid flow dynamics and to decipher the influence of scientific exploration...

Kelps include the largest benthic organisms in the world, and are one of the most successful groups of brown algae. Kelp forests are highly productive ecosystems in coastal regions with strong upwelling boundary currents but, due to their scarce fossil record, little is known of their evolutionary history. They were thought to have radiated in the...

Organisms that colonize wood are subject to a taphonomic tragedy-the richer and more diverse they become, the greater the deterioration of the host wood and the less likely such communities are to be fossilized. Moreover, palaeobotanical studies of fossil wood usually focus on the plant tissue, neglecting the evidence of parasitic, saproxylic, and...

The fossil record of the cephalopod genus Nautilus has been obscured because a few influential taxonomists during the 20th Century decided that fossils similar to Nautilus were instead other genera. We now recognize fossils once classified as species of other genera as species of Nautilus. This includes fossils from Miocene rocks of Taiwan that wer...

Invertebrates living at methane seeps such as mussels and clams gain nutrition through symbiosis with chemosynthetic, chiefly methanotrophic and thiotrophic bacteria. Lipid biomarkers, including their compound-specific carbon stable isotope compositions, extracted from the host tissues are predestined for deciphering the various sources of diets an...

The fossil record of octocorals from Cenozoic marine strata of western North America is quite limited, and they have not been reported previously from rocks in Washington State, USA. Two late Oligocene specimens from the upper part of the Lincoln Creek Formation in western Washington, referred to Radicipes ? sp., are the first fossil record of the...

Here is reported fauna from a Middle Miocene limestone deposit of the Cojímar Formation near the town of Aguacate in the Province of Mayabeque, western Cuba. The fossils are preserved only as internal or external molds, but we identified members of at least eight bivalves and six gastropod families and one solitary coral. The most common taxon is a...

Late Triassic and early Jurassic dikes and fissures in the Dachstein Limestone in the Northern Calcareous Alps harbor mass occurrences of the rhynchonellide brachiopods Sulcirostra juvavica and Halorella amphitoma. To test recent hypotheses about their paleoecology, we characterized these habitats using petrography, carbon stable isotopes, and trac...

A mass occurrence of the thyasirid bivalve Thyasira montanita in a limestone bed, exposed at Punta Montañita on the northern side of the Santa Elena peninsula in southeastern Ecuador, is here identified as an ancient methane-seep deposit. The massive to nodular limestone shows carbonate phases and microfabrics typical of seep limestones, such as ba...

The Miocene epoch (23.03-5.33 Ma) was a time interval of global warmth, relative to today. Continental configurations and mountain topography transitioned toward modern conditions, and many flora and fauna evolved into the same taxa that exist today. Miocene climate was dynamic: long periods of early and late glaciation bracketed a ∼2 Myr greenhous...

The Miocene epoch (23.03–5.33 Ma) was a time interval of global warmth, relative to today. Continental configurations and mountain topography transitioned toward modern conditions, and many flora and fauna evolved into the same taxa that exist today. Miocene climate was dynamic: long periods of early and late glaciation bracketed a ∼2 Myr greenhous...

Phylogenetic analyses using morphological data currently require hand-crafted character matrices, limiting the number of taxa that can be included. Here I explore how Deep Learning and Computer Vision approaches typically applied to image classification tasks, may be used to infer phylogenetic relationships among bivalves. A convolutional neural ne...

Stratigraphic and structural constraints on the initiation and early evolution of the Cascadia convergent margin, following accretion of the igneous Siletzia terrane at 50−45 Ma, remain elusive. This study applies a novel approach based on the combination of Nd, Sr, C and O isotope analyses of the oldest-known methane-seep carbonates (Humptulips Fo...

Marine hydrocarbon seeps are sites of chemosynthetic microbial activity and authigenic carbonate formation. Seep limestones are typified by a range of geochemical signatures of microbial hydrocarbon oxidation, but only few seep deposits reveal mesofabrics that can be regarded as evidence of microbial activity. A Cretaceous methane‐seep limestone fr...

Stratigraphic and structural context of the early evolution of the Cascadia convergent margin, following major subduction reconfiguration associated with accretion of the igneous Siletzia terrane at 50−45 Ma, remains insufficiently understood. Here, we have applied a novel approach that uses combined Nd, Sr and stable isotope analyses of ancient me...

A total of 25 species of mollusks and crustaceans are reported from Oligocene seep deposits in the Talara Basin in northern Peru. Among these, 12 are identified to the species-level, including one new genus, six new species, and three new combinations. Pseudophopsis is introduced for medium-sized, elongate-oval kalenterid bivalves with a strong hin...

The SYNTHESYS consortium has been operational since 2004, and has facilitated physical access by individual researchers to European natural history collections through virtual access to collections through digitisation, with two calls for the programme, the first in 2020 and the second in 2021. The Virtual Access (VA) programme is not a direct digi...

Brachiopods were thought to have dominated deep-sea hydrothermal vents and hydrocarbon seeps for most of the Paleozoic and Mesozoic, and were believed to have been outcompeted and replaced by chemosymbiotic bivalves during the Late Cretaceous. But recent findings of bivalve-rich seep deposits of Paleozoic and Mesozoic age have questioned this parad...

We report on two fossil species of the chemosymbiotic bivalve family Vesicomyidae that were recently collected from Cenozoic strata in Japan. The new species Pleurophopsis matsumotoi is described from the upper Oligocene to lower Miocene Hioki Complex in Kochi Prefecture, and the extant species Calyp-togena pacifica Dall, 1891 is reported from the...

Thirteen fossiliferous limestone deposits from Cenozoic strata in the Talara Basin in northern Peru are identified as ancient methane-seep deposits. Planktonic foraminifera and the existing stratigraphic framework of the Talara Basin indicate an early Oligocene, or possibly late Eocene, age of these deposits. They are found in three distinct areas-...

A new species of the genus Wareniconcha, W. mercenarioides, belonging to the chemosymbiotic bivalve subfamily Pliocardiinae (family Vesicomyidae), is described from a Pliocene methane-seep deposit at Liog-Liog on Leyte Island, Philippines. With a length of almost 12 cm, this species is significantly larger than the six extant species currently cons...

We present a systematic study of late Paleocene macrofauna from methane seep carbonates and associated driftwood in the shallow marine Basilika Formation, Spitsbergen, Svalbard. The fauna is composed of 22 taxa, comprising one brachiopod, 14 bivalves, three gastropods, three crustaceans, and one bony fish. The reported fish remains are among the fi...

The carbonates forming at deep-sea hydrocarbon seeps provide an archive for the source and migration pathways of the seeping fluids. Interpretation of the archived isotopic and elemental signatures is, however, not straightforward because of mixing between the signals of fluids and ambient seawater, limited understanding of subseafloor fluid circul...

Carbonate blocks with silicified fossils were recovered from a newly recognized cold seep deposit, the Satsop Weatherwax site, in the basal Humptulips Formation, along the West Fork of Satsop River in Washington State, USA. The petrography and the stable carbon isotope signature of the carbonate, with values as low as -43.5, indicate that these car...

Diploporitans had subspherical thecae, which usually were attached to hard substrates either directly with an attachment disc at the base of their theca or with a stem and holdfast. After the death of the animal, isolated thecae were easily transported by currents over more or less consolidated sediment. We describe a case where 13 diploporitan the...

M. 2018. Chemosymbiotic bivalves from the late Pliocene Stirone River hydrocarbon seep complex in northern Italy. Acta Palaeontologica Polonica 63: xxx-xxx. Seven species of chemosymbiotic bivalves are described from the late Pliocene Stirone River hydrocarbon seep complex in northern Italy, including one new species and two in open nomenclature. T...

A limestone deposit with an unusual fauna is reported from the late Miocene of northern Italy (Ca’ Fornace site). The petrography of the carbonate and its distinct carbon isotope signature (with δ13C values as low as -57.6‰) clearly identify this limestone as an ancient methane-seep deposit. The dominant faunal elements are serpulid tubes belonging...

Three new bivalve genera and species are described from Upper Triassic hydrocarbon seep deposits from the Kasımlar shales in the Taurus Mountains in southern Turkey. Terzileria gregaria and Kasimlara kosuni belong to the carditiid family Kalenteridae, and Aksumya krystyni belongs to the anomalodesmatan superfamily Pholadomyoidae. A single specimen...

Four new species of the methane seep-inhabiting kalenterid bivalve genus Caspiconcha Kelly in Kelly et al., 2000 are described: Caspiconcha basquensis from the late Albian of northern Spain, C. yubariensis from the late Albian of northern Japan, C. raukumaraensis from the late Albian to mid-Cenomanian of New Zealand, and C. lastsamurai from the Cam...

We present a systematic study of thyasirid bivalves from Cretaceous to Oligocene seep carbonates worldwide. Eleven species of thyasirid bivalves are identified belonging to three genera: Conchocele, Maorithyas, and Thyasira. Two species are new: Maorithyas humptulipsensis sp. nov. from middle Eocene seep carbonates in the Humptulips Formation, Wash...

Deep-sea hydrothermal vents and hydrocarbon seeps host unique ecosystems relying on geochemical energy rather than photosynthesis. Whereas the fossil and evolutionary history of these ecosystems is increasingly well known from the Cretaceous onward, their earlier history remains poorly understood and brachiopods are considered to have played a domi...

The biogeographic distribution of organisms has continuously changed through Earth's history as plate tectonics changed the configurations of land masses, ocean basins, and climate zones. Yet, methods to investigate this dynamic through geologic time are limited. Here, network analysis is used to explore and to visualize the biogeographic history o...

Eleven species of chemosymbiotic bivalves are reported from middle to late Miocene methane seep deposits ( ‘Calcari a Lucina’ ) in the Italian Apennines, including seven new species and one new genus. The new species are Bathymodiolus (s.l.) moroniae and B. (s.l.) miomediterraneus among the Bathymodiolinae and Archivesica aharoni, A. apenninica, A....

Deep-sea hydrothermal vents and methane seeps are inhabited by members of the same higher taxa but share few species, thus scientists have long sought habitats or regions of intermediate character that would facilitate connectivity among these habitats. Here a network analysis of 79 vent, seep, and whale-fall communities with 121 genus-level taxa i...

Elmira is a medium-to-large gastropod of uncertain systematic affinity, which has so far been reported only from a presumably Eocene methane-seep deposit in Cuba. This study reports a mass occurrence of Elmira shimantoensis Kiel and Nobuhara sp. nov. from a Late Cretaceous hydrocarbon-seep deposit in Shikoku, Japan, called the Sada Limestone. Its p...

Invertebrate fossils described from ancient hydrocarbon seep deposits represent diverse groups, e.g., brachiopods, mollusks, decapod crustaceans, worm tubes, and rare echinoderms, but the fossil record of ostracodes from hydrocarbon seep deposits is still very limited, making their ecology and evolutionary history still little known. We found fossi...

Three species of chemosymbiotic bivalves with different inferred sulfide tolerances and life habits from a lower Oligocene seep deposit in eastern Hokkaido, Japan, were investigated for drill holes and scars of durophagous predation. The thyasirid Conchocele bisecta had the lowest inferred sulfide tolerance and showed the highest frequencies of rep...

Tabel S1: locality information; Table S2: referenced occurrence data (the core data of the analysis); Table 3: numbers and probabilities of links between different depth ranges; Figure S1: the biogeographic network when analyzed only with localities with 5 or more taxa

Tabel S1: locality information; Table S2: referenced occurrence data (the core data of the analysis); Table 3: numbers and probabilities of links between different depth ranges; Figure S1: the biogeographic network when analyzed only with localities with 5 or more taxa

Geochemical markers are being increasingly applied to fundamental questions in population and community ecology in marine habitats because they allow inferences on individuals dispersal, but vital effects, small sample size and instrumental limitation are still challenging particularly in deep-sea studies. Here we use shells of the deep-sea bivalve...

We report new examples of Cenozoic cold-seep communities from Colombia, Cuba, the Dominican Republic, Trinidad, and Venezuela, and attempt to improve the stratigraphic dating of Cenozoic Caribbean seep communities using strontium isotope stratigraphy. Two seep faunas are distinguished in Barbados: the late Eocene mudstone-hosted 'Joes River fauna'...

The degradation and preservation affecting the biomarker record of ancient metazoa are not fully understood. We report on a five month experiment on the fate of fatty acids (FAs) during the degradation of recent whale vertebrae (Phocoena phocoena). Whale bones were analysed for extractable FAs and macromolecularly bound n-acyl compounds. Fresh bone...

Modern and Cenozoic deep-sea hydrothermal-vent and methane-seep communities are dominated by large tubeworms, bivalves and gastropods. In contrast, many Early Cretaceous seep communities were dominated by the largest Mesozoic rhynchonellid brachiopod, the dimerelloid Peregrinella, the paleoecologic and evolutionary traits of which are still poorly...

Twenty-nine mollusk species from Late Jurassic to Eocene hydrocarbon seep deposits from California (USA), Japan, New Zealand, and Barbados are described and illustrated. Twenty species belong to Gastropoda and nine to Bivalvia. Seven new species, three new genera, and one new family are introduced. The gastropod Hikidea gen. nov. includes smooth-sh...

Owing to the assumed lack of deep-sea macrofossils older than the Late Cretaceous, very little is known about the geological history of deep-sea communities, and most inference-based hypotheses argue for repeated recolonizations of the deep sea from shelf habitats following major palaeoceanographic perturbations. We present a fossil deep-sea assemb...

Methane seep carbonates preserve information about the history of methane seepage and of the fauna inhabiting these ecosystems. For this information to be useful, a reliable determination of the carbonates’ stratigraphic ages is required, but this is not always available. Here we investigate the using strontium isotope stratigraphy to date fossil m...

A fossil association of potentially chemosymbiotic bivalves is reported from the lower Miocene Shikiya Formation in Kii Oshima Island, Wakayama Prefecture, Japan. The association is dominated by the elongate vesicomyid species Adulomya uchimuraensis (Kuroda, 1931); a second vesicomyid of lower abundance is here described as Archivesica sakoi new sp...

The taphonomic and diagenetic processes by which organic substances are preserved in animal remains are not completely known and the originality of putative metazoan biomolecules in fossil samples is a matter of scientific discussion. Here we report on biomarker information preserved in a fossil whale bone from an Oligocene phosphatic limestone (El...

Three isolated limestone deposits and their fauna are described from a middle Eocene Flysch succession in northwestern Istria, Croatia. The limestones are identified as ancient methaneseep deposits based on fabrics and characteristic mineral phases, δ13Ccarbonate values as low as −42.2‰ and 13C-depleted lipid biomarkers indicative of methane-oxidiz...

Adaptive radiations present fascinating opportunities for studying the evolutionary process. Most cases come from isolated lakes or islands, where unoccupied ecological space is filled through novel adaptations. Here, we describe an unusual example of an adaptive radiation: symbiotic mussels that colonized island-like chemosynthetic environments su...

Late Albian deep-water sediments of the Black Flysch Group in the Basque-Cantabrian Basin (western Pyrenees) preserve a fossil pockmark field including methane seep carbonates and associated macrofauna. The geometry of the pockmarks is reconstructed from repeated lens-shaped turbidite deposits with centrally located carbonate bodies. Early diagenet...

Six Cretaceous methane-seep deposits are reported from the Raukumara Peninsula, eastern North Island, New Zealand. Dinoflagellate dating indicates a Late Albian to mid-Cenomanian age for three deposits from Port Awanui, and a mid-Campanian age for two deposits from Waipiro Bay and for one from Owhena Stream. The dominant petrographic fabric of the...

Six taxa of serpulid polychaetes are reported from early Cretaceous to Miocene seep communities and their ecologic and evolutionary implications are discussed. All studied tubeworms belong to Mesozoic to modern serpulid taxa and not to any of the problematic Paleozoic tube worm clades. They are thus not 'relic taxa' that found refuge in these envir...

Twelve species of lucinid bivalves are reported from late Jurassic to late Miocene methane-seep deposits worldwide. Among them, eight species and two genera are new. Amanocina n. gen. includes Nipponothracia yezoensis from the Cenomanian of Japan as type species, Cryptolucina kuhnpassetensis Kelly, 2000 from the Berriasian of Greenland, A. raukumar...

Fossil chondrichthyan egg capsules have been known for more than 180 years, although the early findings were often misinterpreted as various plant organs like inflorescences or fructifications. Since the first discovery of these fossils our knowledge of their morphological and taphonomical variability, geographical and stratigraphical distribution,...

An isolated limestone deposit occurs within late Eocene to early Oligocene submarine fan deposits of the Tanamigawa Formation in the outskirts of Kushimoto Town in southern Honshu, Japan. The petrography, the very negative carbon isotope signature of early diagenetic cements, and the abundance of chemosymbiotic bivalves, namely thyasirids, vesicomy...

Bathymodiolin mussels are a group of bivalves associated with deep-sea hydrothermal vents and other reducing deep-sea habitats, and they have a particularly rich early Cenozoic fossil record in western Washington State, U.S.A. Here we recognize six species from middle Eocene to latest Oligocene deep-water methane seep deposits in western Washington...

Recent expeditions have revealed high levels of biodiversity in the tropical deep-sea, yet little is known about the age or origin of this biodiversity, and large-scale molecular studies are still few in number. In this study, we had access to the largest number of solariellid gastropods ever collected for molecular studies, including many rare and...

Fossil catshark egg capsules, Scyliorhinotheca goederti gen. et sp. nov., are reported from a Late Eocene deep-water methane-seep calcareous deposit in western Washington State, USA. The capsules are preserved three-dimensionally and some show mineralized remnants of the ribbed capsule wall consisting of small globular crystals that are embedded in...

The range of substrates that the bone-eating marine worm Osedax is able to consume has important implications for its evolutionary history, especially its potential link to the rise of whales. Once considered a whale specialist, recent work indicates that Osedax consumes a wide range of vertebrate remains, including whale soft tissue and the bones...