Paleontology is the study of fossils. Although most people think of fossils as only being bones and shells, this research field also focuses on fossilized soft tissues, such as blood vessels. Using fine-scale techniques allows us to investigate the internal anatomy of Triassic vertebrates.

The species of the brachiopod genus Terebratella d'Orbigny, which does not correspond to any one reported hitherto from the upper Eocene-? lower Oligocene La Meseta Formation of Seymour Island, West Antarctica but showing a strong affinity to the Recent T. inconspicua (Sowerby), is described.

Septal neck-siphuncular complex has been redescribed In Triassic (Carnian) Stolleyites tenuis (Stolley). Ammonites whose septal necks change orientation from retrochoanitic through intermediate to prochoanitic may be divided into two categories: dorsoprogressive and ventroprogressive. In the former category, the initial changes in the direction of septal necks orientation occur dorsally; in the latter, the ventral side exhibits more progressive changes. Among forms with siphuncular complex adjacent to the ventral wall, i.e., without a septum between the neck and ventral wall in the medial plane, the changes towards prochoanitic septal neck may begin in the ventrolateral part. The circumsiphonal invagination in those forms did not include the ventral part and their proper interpretation cannot rely on the medial plane only. Primary lamination and primary fibrous structure of the siphuncular tube had been described, as well as the microstructure of the distal tip of cuff and auxiliary deposit.

A new species of genus Panopea Menard de la Groye, named P. (P). andreae sp. n. is described in detail. It is the most common of bivalve species recorded in the Destruction Bay Formation (Early Miocene) of King George Island (South Shetland Islands, West Antarctica). The bivalve material collected includes in addition: P. (P) aff. worthingtoni Hutton, Eurhomalia cf. antarctica (Shermann and Newton) and E. cf. newtoni (Wilcknes).

The ostracod fauna were examined from the Kapp Starostin Formation sequences (Upper Permian) from West Spitsbergen (Svalbard). The ostracod taxa are mainly confined to 3 superfamilies: Kirkbyacea, Healdiacea and Bairdiacea. 11 taxa are identified. One new species, Kindlella bellsundi is proposed. The ostracod assemblage dominated by kirkbyacean taxa is related to open shelf marine environment.

The organodetritic, sandy limestones of the Treskelodden Formation (Late Gzhelian to Early Artinskian) investigated in outcrops at Treskelen Peninsula, Hyrnefjellet mount and Polakkfjellet mount of south Spitsbergen, contain rich foraminiferal assemblages. Fifty eight foraminiferal species of twenty three genera, including two new species (Hemigordius hyrnefjelleti sp. nov. and Midiella arctica sp. nov.) have been identified. Three foraminiferal zones have been defined, with ages of Late Asselian (Pseudofusulinella occidentalis), Sakmarian (Midiella ovata – Calcitornella heathi) and Early Artinskian (Hemigordius hyrnefjelleti – Midiella arctica). Sedimentary features and the biotic history of the studied succession records a Late Paleozoic cooling trend that stays in accordance with Pangaea’s shift to the north.

Roemeripora tollinoides sp. n. (Anthozoa, Tabulata) is described from Upper Carboniferous strata of SW Nordenskiöld Land (Ingeborgfiellet), Bellsund area in West Spistbergen (Svalbard). The new species is characteristic for a phacelo-cerioid structure of entire corallum.

New coral taxa Tetraporinus siedlecka sp. n. and Roemeripora aspinosa major ssp. n. are erected from the Lower Permian (Sakmarian and Artinskian) Treskelodden Formation of Hornsund area, Spitsbergen and Syringopora sp. similar to S. subreticulata Nowiński, 1991 are described. Studies on stable isotope ratios of carbon and oxygen in the skeletons of tabulate and rugose corals from Hyrnefjellet and Treskelen areas show that these organism did not frac­tion the isotopes to much. The differences in isotope fractionation, both for carbon and oxygen, reached 2 ‰ comparable to the concurring brachiopods, accepted as reference level.

This is a second paper dealing with juvenile and little known Mesozoic gastropods from Siberia and the Timan region. This part contains description of gastropods belonging to Neogastropoda and Heterobranchia. Described are 16 species, five of them are new. They are: Sulcoactaeon uralicus, S. timanicus, S. bojarkensis (Bullinidae), Vasjugania vasjuganensis (Acteonidae), and Biplica siberica (Ringiculidae). The new genus Vasjugania (Acteonidae) is proposed. Eight species are left in the open nomenclature. The protoconch of Siberian Khetella, illustrated here for the first time, suggests that this genus belongs to Purpurinidae and the whole family is a possible stem group for the Neogastropoda. Apart from Khetella the Siberian fauna seems to be of cosmopolitan character having common elements both with Europe and North America.

This publication begins series of papers on taxonomy of juvenile and little known Mesozoic gastropods from Siberia and Timan region (= Pechora Basin). First part contains general part with geological framework followed by the paleontological part on taxonomy of Vetigastropoda and Caenogastropoda (exclusive of Neogastropoda). Described are 15 species of gastropods. Three of them are new. They are Chuelskia siberica (Trochidae), Ageria gankinensis (Epitoniidae), and Dzikella chuzikovensis (superfamily and family uncertain). Moreover, described is a new genus Chuelskia (Trochidae). Eight species are left in the open nomenclature. The Siberian gastropods belong mostly to the cosmopolitan fauna while the gastropods of Timan region are the same as those already described from Novaja Zemlja Islands.

Productacean brachiopod assemblages are described from 10 taphocoenoses from various facies of the Upper Permian Kapp Starostin Formation in Spitsbergen. Time and space relationships among the investigated phena are based upon a previously established chronostratigraphic correlation of the strata. 15 productacean species are distinguished, based upon analysis of their morphology and ecology. Their paleontological descriptions take into account the ranges of their ecophenotypic variation. Shells adapted to three modes of life are recognized among the considered Productacea: (1) forms stabilizing within loose bottom sediments, (2) forms floating at the surface of soft substrates, and (3) forms living just below the surface of quaggy substrates. Distribution of the productacean assemblages in the Kapp Starostin Formation is analyzed within the framework of a reconstruction of the history of the Permian sea in this area. The main ecological controls upon this distribution include stratification of the water, substrate suitability for settlement, and coastal influences on the marine environment. Because of their spatially limited distribution and unrecognized evolution within the considered time interval, the investigated brachiopods cannot be employed for biochronostratigraphy.

A few specimens of a macroporid bryozoan were collected, from the Eocene La Meseta Formation from Seymour (Marambio) Island, Antarctic Peninsula. Based on the morphology of the studied specimens Macropora antarctica sp.n. has been erected. This is the stratigraphically oldest species of the genus which exhibits a number of similarities with the Tertiary fossils and some Recent macroporids reported from the Southern Hemisphere i.e., Australia, New Zealand and South America.

Eocene penguin remains from Seymour Island (Antarctica) are so far the oldest−known record of extinct Sphenisciformes. Rich Argentineand Polish collections of penguin bones from the La Meseta Formation are taxonomically revised on tarsometatarsal morphology. Two genera and four species are erected: Mesetaornis polarisgen. et sp. n., Marambiornis exilisgen. et sp. n., Delphinornis arctowskiisp. n. and D. gracilissp. n. Moreover, the diagnoses of already described species: Anthropornis nordenskjoeldi, A. grandis, Palaeeudyptes klekowskii, P. gunnari, Archaeospheniscus wimani and Delphinornis larseniare revised as well. Gradual cooling of climate, changes of environment andtrophic relationships, that lasted several millions years, were most probably responsible forthe intense speciation and taxonomic diversification of the Middle–Late Eocene La Meseta penguins.

Skeletal remains of penguins from the Eocene La Meseta Formation (Seymour Island, Antarctica) constitute the only extensive fossil record of Antarctic Sphenisciformes. No articulated skeletons are known, and almost all fossils occur as single isolated elements. Most of the named species are based on tarsometatarsi (for which the taxonomy was revised in 2002). Here, 694 bones (from the Polish collection) other than tarsometatarsi are reviewed, and allocated to species. They confirm previous conclusions and suggest that ten species grouped in six genera are a minimal reliable estimate of the Eocene Antarctic penguin diversity. The species are: Anthropornis grandis, A. nordenskjoeldi, Archaeospheniscus wimani, Delphinornis arctowskii, D. gracilis, D. larseni, Marambiornis exilis, Mesetaornis polaris, Palaeeudyptes gunnari and P. klekowskii. Moreover, diagnoses of four genera (Anthropornis, Archaeospheniscus, Delphinornis and Palaeeudyptes) and two species (P. gunnari and P. klekowskii) are supplemented with additional, non-tarsometatarsal features. Four species of the smallest penguins from the La Meseta Formation (D. arctowskii, D. gracilis, M. exilis and M. polaris) seem to be the youngest taxa within the studied assemblage - their remains come exclusively from the uppermost unit of the formation. All ten recognized species may have co-existed in the Antarctic Peninsula region during the Late Eocene epoch.

Brachiopods are reported for the first time from the Lower Miocene Cape Melville Formation of King George Island, South Shetland Islands, West Antarctica. Two genera, Liothyrella Thomson and Paraldingia Richardson have been identified. This is the first occurrence of Paraldingia in Antarctica.

Penguin bones from the La Meseta Formation (Seymour Island, Antarctic Peninsula) are the only record of Eocene Antarctic Sphenisciformes. Being an abundant component of the youngest unit of the formation (Telm7), they are not so common in earlier strata. Here, I present the oldest penguin remains from the La Meseta Formation (Telm1-Telm2), often bearing close resemblance to their counterparts from younger units. Addressing the recent findings in fossil penguin systematics, I suggest there is too weak a basis for erecting new Eocene Antarctic taxa based on non-tarsometatarsal elements of penguin skeletons, and considering Oligocene species part of the studied assemblage. Finally, I conclude if the common ancestor of extant Sphenisciformes lived in the Eocene Antarctic (as suggested recently), penguins referred to Delphinornis seem to be prime candidates to that position.

Solitary corals of the genus Flabellum are described from the Lower Oligocene glaciomarine strata of the Polonez Cove Formation of King George Island, West Antarctica. This is the oldest record of the genus from Antarctica.

An additional account on the Oligocene cyclostome Bryozoa has been made from the glaciomarine sediments of the Low Head Member (= Pecten conglomerate of Barton 1965) of the Polonez Cove Formation on King George Island (South Shetland Island, West Antarctica). The following genera have been recognized for the first time in Paleogene of Antarctica: Crista, Bicrisia, Exidmonea, Filisparsa and Mecynoecia. Paleoecological interpretation of the bryozoan assemblage implies that the fauna lived in shallow water at a depth of around 50 m.

An isolated, deciduous incisor of an archaic whale found in the upper part of the La Meseta Formation (Telm7) is tentatively assigned to the Archaeoceti. The strata from which the tooth was recovered are of Late Eocene (Priabonian) age, and previous reports indicate that they contain the remains of Dorudontinae (Archaeoceti) and Llanocetidae (Mysticeti). The tooth is similar in shape, size and ornamentation to the milk teeth of Zygorhiza. The enamel is mostly prismatic, with prism sheats generally open, except for the outermost layer, which is aprismatic. The Schmelzmuster consists of radial and decussating enamel types. The decussating zone has distinct Hunter-Schreger bands (HSB), usually consisting of 10–12 prisms. It is bordered by an external zone built of radial enamel extending for 22% of the enamel thickness and an internal, starting zone, with less developed HSB, occupying 9% of the enamel thickness. The interprismatic matrix is parallel to the prism direction. An archaeocete origin of the tooth is suggested by its enamel features, typical for the group. However, additional study of the Llanocetidae enamel structure is needed for final identification.

This report describes aims and preliminary results of geological fieldwork carried out by a joint Argentine-Polish party on Seymour (Marambio) and Cockburn islands. Antarctic Peninsula, during austral summer of 1987 88. Seymour Island exposes chiefly shallow-marine, fossiliferous siliciclastic sediments that form an upper, 2000 m thick part in the Mesozoic-Tertiary backarc basin-infill of the Antarctic Peninsula. The fieldwork centered on paleontology and sedimentology of the La Meseta Formation (upper Eocene- ?lower Oligocene), although some observations of older deposits were carried out also. Clupeoid fishes were discovered in the La Meseta Formation. This is the first record of such fish fossils on the Antarctic continent.