Krzysztof Hryniewicz

• PhD
• Researcher at Polish Academy of Sciences

During the Triassic, fish were the most abundant group of marine vertebrates-in terms of both species richness and number of niches they occupied-as indicated by their rich skeletal record. However, the Triassic ichthyolith record is relatively poor, unlike that from younger time periods, what skews the published palaeontological data heavily towar...

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...

For over ten years, the Lower to Upper Tithonian boundary beds cropping out in the Owadów-Brzezinki quarry have yielded numerous fossils of ammonites, bivalves, brachiopods, xiphosurans, decapods, insects, and vertebrates-including actinopterygian fishes and various reptiles and others, all of which exhibit fine preservation of their anatomical det...

We report a Valanginian (Early Cretaceous) otolith-based ichthyofauna from a section at Wąwał in central Poland. We describe one new genus (Palaeoargentina gen. nov.), six new otolith-based species (Pteralbula polonica sp. nov., Protalbula pentangularis sp. nov., Kokenichthys kuteki sp. nov., Protoelops gracilis sp. nov., Palaeoargentina plicata sp...

We report the first cephalopod statoliths from the Early Cretaceous. These unique microfossils fill the gap in the fossil record between Jurassic and Cenozoic forms and are more similar to the former. We compare the morphology of the Mesozoic forms with the statoliths from Recent and Cenozoic decabrachians. This comparison shows the closest resembl...

Despite much effort aimed to better constrain the fossil record of chemosynthesis-based communities, our understanding of their early evolution remains fragmentary. Until recently, a dominant perception was that, unlike the Cenozoic, bivalve-dominated chemosynthesis-based ecosystems, the Palaeozoic to mid-Mesozoic methane seeps and hydrothermal ven...

Precipitation of cements forming methane-derived carbonates is inherent to marine hydrocarbon seep environments. Carbonate deposits enriched in methanogenic carbon are found in ancient rock formations as old as the Silurian. In contrast to their recent equivalents, they are mostly found on land in uplifted ancient sedimentary formations. Unlike the...

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...

Sponges are well known from recent vents and seeps, but most of them are background organisms that may occur elsewhere. Only a few are proven to be dependent on chemosynthesis. Conversely, sponges are only rarely reported from ancient hydrothermal vent and cold seep deposits. Here we present an overview of present-day sponges reported from such com...

This chapter summarizes information about ancient hydrocarbon seeps from around the world. The information is organized into two tables, one comprising both Americas and Antarctica, the other Africa, Arctic, Asia, Europe, and New Zealand. Within each table, entries are organized by continent, and within the continent, by country, region, and state....

The studied seep carbonates from Tsushima, Japan, are embedded within marine siliciclastics of the lower Miocene Taishu Group and represent the earliest evidence of hydrocarbon seepage in the Sea of Japan. In contrast to Miocene and Pliocene examples from Honshu, which are often found above anticlines, the seeps from Tsushima formed within a pull-a...

Despite much scientific effort aimed over the past three decades to better constrain the fossil record of chemosynthesis-based communities, our understanding of their early evolution remains fragmentary. Until recently, a dominant perception was that, unlike the Cenozoic, bivalvedominated chemosynthetic ecosystems, the Paleozoic to mid-Mesozoic met...

The paper reports rare occurrence of deep-water solemyid and lucinid bivalves from Cenozoic sequences of Outer Eastern Carpathians, Ukraine. The studied bivalves occur in the Eocene Pasichna Formation, represented by deep-water marls and pelagic limestones intercalated with thin-bedded calcareous sandstones yielding material re-deposited from shall...

This is a short report about the first Cenozoic shark fossil from Svalbard. The specimen derives from the late Paleocene greenish sandstone of the Grumantbyen Formation, which is exposed in Fossildalen on the western side of Colesbukta on Spitsbergen. The single tooth is assigned to the Paleogene sand tiger shark genus Striatolamia that also is kno...

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...

In the Mesozoic seas, the apex predators were reptiles. From the Arctic archipelago of Svalbard, the Spitsbergen Mesozoic Research Group has excavated numerous well preserved marine reptile skeletons in order to understand the biology of these animals and the environment they lived in. The work of eleven field seasons has made this one of the large...

Two species of the gastropod family Pseudomelatomidae, genus Boreocomitas, including the new species B. inouei, are described from the Paleocene (upper Selandian to lowest Thanetian) Katsuhira Formation in eastern Hokkaido, Japan. These species represent the first Paleocene record of Boreocomitas. The paper discusses also the new recognition of spe...

This paper discusses some latest Emsian (Early Devonian) bivalves from marls of the Amerboh Group, Hamar Laghdad (Morocco). Species belonging to five identifiable genera are present in the examined material: Panenka BARRANDE, 1881, Hercynella KAYSER, 1878, Jahnia RŮŽIČKA & PRANTL, 1960, Grammysioidea MILLER, 1877 and Patrocardia FISCHER, 1887. In a...

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...

One of the most striking features of modern chemosynthesis-based ecosystems surrounding methane seeps is the presence of abundant chemosymbiotic bivalves. However, such accumulations have rarely been reported from Palaeozoic to mid-Mesozoic seeps, and it is widely thought that general trends in the evolution of chemosynthetic communities paralleled...

Eleven gastropod species from seven latest Jurassic–earliest Cretaceous hydrocarbon seep deposits from central Spitsbergen, Svalbard are described and illustrated. Six new species and one new genus are introduced. Sassenfjordia gen. nov. is tentatively classified as a naticoid and is characterized by a naticiform gross teleoconch morphology and a l...

During field mapping of Ellef Ringnes Island, Canadian Arctic Archipelago, 139 isolated Early Cretaceous methane seep deposits were found from 75 field sites. Stable isotopes of the carbonates have values of δ¹³C = −47‰ to −35‰ and δ¹⁸O = −4.0‰ to +0.7‰. Isoprenoids in organics from one of the seeps are significantly depleted in ¹³C, with the most...

During field mapping of Ellef Ringnes Island, Canadian Arctic Archipelago, 139 isolated Lower Cretaceous methane seep deposits were found from 75 field sites. Stable isotopes of the carbonates have values of δ13C= -47‰ to -35‰ and δ18O= -4.0‰ to +0.7‰. Isoprenoids in organics from one of the seeps are significantly depleted in 13C, with the most ne...

A fauna of bivalve molluscs is described from methane seep carbonates of the Middle Devonian (c. 390 Ma) Hollard Mound in the eastern Anti-Atlas, Morocco. We describe a new modiomorphid genus Ataviaconcha gen. nov. with the type species Ataviaconcha wendti sp. nov. This is a very large, semi-infaunal species occurring in large colonies similar to t...

Here we describe a Paleocene-aged methane seep locality and an associated layer of sunken wood, from Fossildalen on Spitsbergen, Svalbard, hosted in offshore to prodelta siltstones of the Basilika Formation, Van Mijenfjorden Group. The fossiliferous seep carbonates were first identified in museum collections from expeditions in the 1920s and 1970s,...

We present a re-description of the pholadid bivalve from the Oligocene Polonez Cove Formation, King George Island, West Antarctica, previously identified as Penitella sp. The study is based on a collection of 210 specimens, preserved exclusively in life position in flask-shaped Gastrochaenolites type borings which have been subsequently buried by g...

Dimerelloids are the most common and characteristic brachiopods for ancient hydrocarbon seeps and hydrothermal vents. They often occur in mass accumulations similar to these of chemosymbiotic bivalves. Other brachiopods are much less common and in several instances they occur seemingly fortuitously at hydrocarbon seeps. The best known association i...

The paper describes Late Jurassic–Early Cretaceous seep carbonate boulders from the Russian Arctic island of Novaya Zemlya, collected in 1875 by A.E. Nordenskiöld during his expedition to Siberia. The carbonates are significantly depleted in heavy carbon isotopes (δ13C values as low as ca. − 40‰) and show textures typical for carbonates formed unde...

Latest Jurassic–earliest Cretaceous hydrocarbon seeps from Spitsbergen, Svalbard, are known to contain unusual fauna, lacking most of the species characteristic for roughly coeval seep deposits. This study summarizes and analyses the fauna from 16 seep carbonate bodies from Spitsbergen to explain its composition. The seeps formed in a shallow epico...

Serpulid polychaete tubes are described from Volgian-Ryazanian sediments (?Pyrgopolon decorata (Stolley, 1912), ?Pyrgopolon aff. nodulosum (Lundgren, 1883)) and four contemporaneous hydrocarbon seep deposits (?Pyrgopolon aff. nodulosum, ?Pyrgopolon sp. A, Propomatoceros sp. A, Nogrobs aff. quadricarinata Münster in Goldfuss, 1831) from Spitsbergen,...

Late Jurassic–Early Cretaceous (Late Volgian–latest Ryazanian) rhynchonellate brachiopods are described from eight out of 15 hydrocarbon seep deposits in the Slottsmøya Member of the Agardhfjellet Formation in the Janusfjellet to Knorringfjellet area, central Spitsbergen, Svalbard. The fauna comprises rhynchonellides, terebratulides (terebratuloids...

Methane-derived authigenic carbonate (MDAC) mound features at the Codling Fault Zone (CFZ), located in shallow waters (50 to 120 m) of the western Irish Sea were investigated and provide a comparison to deep sea MDAC settings. Carbonates conststed of aragonite as the major mineral phase, with δ13C depletion to -50‰ and δ18O enrichment to ~ 2‰. Thes...

The bivalve fauna from the latest Jurassic–earliest Cretaceous hydrocarbon seep deposits from central Spitsbergen, Svalbard comprises at least 17 species, four of which belong to chemosymbiotic taxa often found at seeps. These are the solemyid Solemya (Petrasma) cf. woodwardiana; Nucinella svalbardensis sp. nov., which belongs to a group of large N...

The high variability of rocks is one of the basic values of the nature in the Tatra Mountains. Part of them includes the sedimentary rocks, which originated in environmental and geographic conditions different than today, on land, in shallow or deep sea, mainly in the Mesozoic and Cenozoic eras. These rocks build the lower (regle) and higher (wierc...

We report on the discovery of large cephalopod arm hooks (mega−onychites) from the Kimmeridgian and Volgian of Spitsbergen (Agardhfjellet Formation). This includes a largely uncompressed hook in a seep carbonate,with preservation of surface sculpture. We suggest the use of logarithmic spirals as morphological descriptors for the outer part of cepha...

This paper presents a detailed analysis of microfacies of nine of the 15 hydrocarbon seep carbonates recorded from the Sassenfjorden area, Svalbard. These Late Volgian-latest Ryazanian carbonates have been found in the black shales of the uppermost Slottsmøya Member, Agardhfjellet Formation. The interval is characterised by a low sedimentation rate...

Paleontological fieldwork on Spitsbergen, 2004-2011, has revealed the presence of abundant plesiosaur and ichthyosaur remains, a series of 15 seep carbonate bodies, as well as a rich invertebrate fauna from the Upper Jurassic – Lower Cretaceous Slottsmøya Member of the Agardhfjellet Formation, a 70-100 metre-thick unit of dark grey to black shale a...

A collection of 55 well preserved ammonite specimens from hydrocarbon seep carbonate bodies from the Slottsmøya Member, Agardhfjellet Formation, in the Sassenfjorden area, Spitsbergen, is described and used as a basis for a chronostratigraphical interpretation of the seep deposits. The ammonites enable us to give a detailed biostratigraphical frame...

Fifteen carbonate bodies, interpreted as having been formed at hydrocarbon seeps, have been found in the Sassenfjorden area of Spitsbergen, Svalbard. The bodies, up to 5 m wide, are found in the siltstones and mudstones of the uppermost Slottsmøya Member, in the Upper Jurassic to lowermost Cretaceous Agardhfjellet Formation. The age of the seeps is...