| 1. |
- Adrian, Brent, et al.
(författare)
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New Miocene Carnivora (Mammalia) from Moruorot and Kalodirr, Kenya
- 2018
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Ingår i: Palaeontologia Electronica. - : Coquina Press. - 1935-3952 .- 1094-8074. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- We describe new carnivoran fossils from Kalodirr and Moruorot, two late EarlyMiocene sites in the Lothidok Formation of West Turkana, Kenya. The fossils include anew species of viverrid, Kichechia savagei sp. nov., a new genus and species of felid,Katifelis nightingalei gen. et sp. nov., and an unidentified musteloid. We also reportnew records of the amphicyonid Cynelos macrodon. These new fossils increase theknown diversity of African Early Miocene carnivorans and highlight regional differencesin Africa.
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| 2. |
- Bengtson, Stefan, 1947-, et al.
(författare)
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Chancelloriids of the Cambrian Burgess Shale
- 2015
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Ingår i: Palaeontologia Electronica. - 1935-3952 .- 1094-8074. ; 18:1, s. 1-67
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Tidskriftsartikel (refereegranskat)abstract
- The cactus-like chancelloriids from the Middle Cambrian Burgess Shale are revised on the basis of Walcott’s (1920) original collections and new material containing several hundred specimens collected by Royal Ontario Museum field expeditions from 1975 to 2000. Walcott’s interpretation of chancelloriids as sponges was based on a misinterpretation of the dermal coelosclerites as embedded sponge-type spicules, an interpretation that further led to the lumping of three distinct taxa into one species, Chancelloria eros Walcott, 1920. The other two taxa are herein separated from C. eros and described as Allonnia tintinopsis n.sp. and Archiasterella coriacea n.sp., all belonging to the Family Chancelloriidae Walcott, 1920. Chancelloriids were sedentary animals, anchored to shells or lumps of debris in the muddy bottom, or to sponges, or to other chancelloriids. They had a radially symmetrical body and an apical orifice surrounded by a palisade of modified sclerites. Well-preserved integuments in Al. tintinopsis and Ar. coriacea do not show any ostium-like openings. Neither is there any evidence for internal organs, such as a gut. Partly narrowed specimens suggest that the body periodically contracted from the attached end to expel waste material from the body cavity. Chancelloriids were close in organization to cnidarians but shared the character of coelosclerites with the bilaterian halkieriids and siphogonuchitids. The taxon Coeloscleritophora is most likely paraphyletic.
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| 3. |
- Chris, Mays, 1983-, et al.
(författare)
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Pushing the limits of neutron tomography in palaeontology: Three-dimensional modelling of in situ resin within fossil plants
- 2017
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Ingår i: Palaeontologia Electronica. - California : Coquina Press. - 1935-3952 .- 1094-8074. ; 20:3, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- Computed tomography is an increasingly popular technique for the non-destructivestudy of fossils. Whilst the science of X-ray computed tomography (CT) has greatlymatured since its first fossil applications in the early 1980s, the applications and limitationsof neutron tomography (NT) remain relatively unexplored in palaeontology. Thesehighest resolution neutron tomographic scans in palaeontology to date were conductedon a specimen of Austrosequoia novae-zeelandiae (Ettingshausen) Mays and Cantrillrecovered from mid-Cretaceous (Cenomanian; ~100–94 Ma) strata of the ChathamIslands, eastern Zealandia. Previously, the species has been identified with in situ fossilresin (amber); the new neutron tomographic analyses demonstrated an anomalouslyhigh neutron attenuation signal for fossil resin. The resulting data provided astrong contrast between, and distinct three-dimensional representations of the: 1) fossilresin; 2) coalified plant matter; and 3) sedimentary matrix. These data facilitated ananatomical model of endogenous resin bodies within the cone axis and bract-scalecomplexes. The types and distributions of resin bodies support a close alliance withSequoia Endlicher (Cupressaceae), a group of conifers whose extant members areonly found in the Northern Hemisphere. This study demonstrates the feasibility of NTas a means to differentiate chemically distinct organic compounds within fossils.Herein, we make specific recommendations regarding: 1) the suitability of fossil preservationstyles for NT; 2) the conservation of organic specimens with hydrogenous consolidantsand adhesives; and 3) the application of emerging methods (e.g., neutronphase contrast) for further improvements when imaging fine-detailed anatomical structures.These findings demonstrate that we are still far from reaching the conceptuallimits of NT as a means of virtually extracting fossils, or imaging their internal anatomyeven when embedded within a rock matrix.
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| 4. |
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| 5. |
- Jerve, Anna, et al.
(författare)
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Morphology and histology of acanthodian fin spines from the late Silurian Ramsåsa E locality, Skåne, Sweden
- 2017
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Ingår i: Palaeontologia Electronica. - : COQUINA PRESS. - 1935-3952 .- 1094-8074. ; 20:3
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Tidskriftsartikel (refereegranskat)abstract
- Comparisons of acanthodians to extant gnathostomes are often hampered by the paucity of mineralized structures in their endoskeleton, which limits the potential preservation of phylogenetically informative traits. Fin spines, mineralized dermal structures that sit anterior to fins, are found on both stem-and crown-group gnathostomes, and represent an additional potential source of comparative data for studying acanthodian relationships with the other groups of early gnathostomes. An assemblage of isolated acanthodian fin spines from the late Silurian Ramsasa site E locality (southern Sweden) has been reconstructed in 3D using propagation phase contrast synchrotron X-ray microtomography (PPC-SR mu CT). The aim is to provide morphological and taxo-nomical affinities for the spines by combining morphology and histology with the taxo-nomical framework previously established for the site mainly based on isolated scales. The high-resolution scans also enable investigations of the composition and growth of acanthodian fin spines when compared to similar studies of extinct and extant gnathostomes. In total, seven fin spine morphotypes that have affinities to both Climatiidae Berg 1940 and Ischnacanthiformes Berg 1940 are described. The majority are interpreted as median fin spines, but three possible paired spines are also identified. The spines display differences in their compositions, but generally agree with that presented for climatiids and ischnacanthiforms in previous studies. Their inferred growth modes appear to be more similar to those of fossil and extant chondrichthyan fin spines than to those described from placoderms and stem-osteichthyans, which is congruent with the emerging view of acanthodians as stem-chondrichthyans.
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| 6. |
- McLoughlin, Stephen, et al.
(författare)
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Fossil clitellate annelid cocoons and their microbiological inclusions from the Eocene of Seymour Island, Antarctica
- 2016
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Ingår i: Palaeontologia Electronica. - Palaeontological Association. - 1935-3952 .- 1094-8074. ; 19:1.11A, s. 1-27
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Tidskriftsartikel (refereegranskat)abstract
- Clitellate annelids have a meagre body fossil record but they secrete proteinaceouscocoons for the protection of eggs that, after hardening, are readily fossilizedand offer a largely untapped resource for assessing the evolutionary history of thisgroup. We describe three species of clitellate cocoons (viz., Burejospermum seymourensesp. nov., B. punctatum sp. nov. and Pegmatothylakos manumii gen. et sp. nov.)from the lower Eocene La Meseta Formation, Seymour Island, Antarctica. Thecocoons probably derive from continental settings and were transported to, and preservedwithin, nearshore marine to estuarine environments. The cocoons provide thefirst evidence of commensal or parasitic relationships in the Eocene continental ecosystemsof Antarctica. Moreover, numerous micro-organisms and the oldest fossilizedexamples of animal spermatozoa are preserved as moulds within the consolidatedwalls of the cocoons. Fossil annelid cocoons offer potential for enhanced palaeoenvironmentalinterpretation of sediments, correlation between continental and shallowmarinestrata, and improved understanding of the development of clitellate annelidreproductive traits and the evolutionary history of soft-bodied micro-organisms in general.
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| 7. |
- Rabiniak, Emilia, et al.
(författare)
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Late Pleistocene and Holocene pikas (Mammalia, Lagomorpha) from Europe and the validity of Ochotona spelaea : New insights based on mtDNA analysis
- 2023
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Ingår i: Palaeontologia Electronica. - : Coquina Press. - 1935-3952 .- 1094-8074. ; 26:1
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Tidskriftsartikel (refereegranskat)abstract
- Pikas were among small mammals that inhabited mammoth steppes during the last glacial. The evolutionary history of ochotonids in Europe is relatively well studied, although the taxonomic status of many described forms remains ambiguous, and the majority of extant species of the genus Ochotona are poorly represented in the fossil record. The present study aims to analyse the taxonomic relationships of a sample of Late Pleistocene-Holocene pikas based on mtDNA data and to clarify the status of the species described from Europe. A phylogenetic analysis has revealed that pikas form two large clades: one includes O. pusilla and the other includes the extant Asian and North American species. The study of haplotypes has shown similar results. The analysis supports the view that in the Late Pleistocene and Holocene O. pusilla was distributed throughout Europe, and its geographic range has contracted to the east until reaching its modern limits. The analysis of samples provided evidence that O. pusilla had survived in Eastern Europe until relatively recently and disappeared only about 150 years ago. The molecular data inferred from mtDNA do not support the species status of O. spelaea, despite morphological differences possibly related to the particular ecology of the Late Pleistocene.
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| 8. |
- Skovsted, Christian, 1974-, et al.
(författare)
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Depth related brachiopod faunas from the lower Cambrian Forteau Formation of southern Labrador and western Newfoundland, Canada
- 2017
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Ingår i: Palaeontologia Electronica. - : Coquina Press. - 1935-3952 .- 1094-8074. ; 20:3, s. 1-52
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Tidskriftsartikel (refereegranskat)abstract
- A diverse fauna of organophosphatic brachiopods is described from the late early Cambrian (Series 2, Stage 3-4) Forteau Formation of southern Labrador and western Newfoundland. The total fauna includes 11 species representing a wide selection of Cambrian brachiopod groups. Three distinct assemblages are recognized: Assemblages1 and 2 are found in shallow water carbonates in association with archaeocyathans in southern Labrador and the western side of the Great Northern Peninsula of western Newfoundland. Assemblage 3 is found in a distal shelf setting of Gros Morne National Park. Assemblages 1 and 2 are found in stratigraphic continuity and definetwo brachiopod biozones, a lower Hadrotreta taconica zone and a higher Paterina zone, respectively. The presence of H. taconica in brachiopod Assemblage 3 possibly indicates time equivalence of Assemblage 1 but in a deep water setting. The identification of distinct time equivalent brachiopod Assemblages (1 and 3) in shallow and deep water environments of the Forteau Formation allow for the first time an analysis of environmental constraints determining the distribution of individual brachiopod taxa in the lower Cambrian succession of eastern Laurentia. Comparison to faunas from other areas indicates that the identified distributional patterns can be extended to other brachiopod faunas found along the Cambrian palaeocoast/margin of eastern Laurentia. The study indicates that specific brachiopod taxa can be used as indicators of palaeodepth; Botsfordia caelata in shallow environments and Eoobolus priscus and Eothele tubulus in deeper water. The following new taxa are described: Kyrshabaktella diabolan. sp., Pustulobolus triangulus n. gen et n. sp., Acrothyra bonnia n. sp.
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| 9. |
- Villa, Andrea, et al.
(författare)
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Miocene and Pliocene amphibians from Hambach (Germany) : New evidence for a late Neogene refuge in northwestern Europe
- 2024
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Ingår i: Palaeontologia Electronica. - 1935-3952 .- 1094-8074. ; 27:1
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Tidskriftsartikel (refereegranskat)abstract
- The Hambach lignite mine in northwestern Germany is a renowned fossil locality, which has yielded remains of several vertebrates dated back to the Middle Miocene and the Late Pliocene. Among these is a recently-described and peculiar proteid urodele, Euronecturus grogu, currently known only from the Middle Miocene level in Hambach. Here, we provide detailed descriptions and identifications of the remaining fossil amphibians (both urodeles and anurans) from the Hambach mine, in total identifying at indet., Pelobatidae indet., Hyla sp., Pelophylax sp., Rana sp.) and at least nine Late Ranidae indet.). The high diversity of amphibians in both Miocene and Pliocene levels at Hambach supports a very humid climate persisting in the area for most of the Neogene, possibly originating a refugium for these animals in northwestern Europe that persisted until the Late Pliocene (and possibly even the Early Pleistocene). Urodeles such as Palaeoproteus and Mioproteus and anurans such as Latonia, the palaeobatrachids, and possibly Eopelobates are all significant occurrences in such a northern latitude at the end of the Pliocene, a period when southward withdrawal of thermophilic animals as well as the first effects of a deteriorizing climate ultimately leading to the Quaternary glaciation had already started in the European continent.
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| 10. |
- Vinn, Olev, et al.
(författare)
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Diverse endobiotic symbiont fauna from the late Katian (Late Ordovician) of Estonia
- 2022
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Ingår i: Palaeontologia Electronica. - : Paleontological Society. - 1935-3952 .- 1094-8074. ; 25:3
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Tidskriftsartikel (refereegranskat)abstract
- 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 here reported from bryozoans for the first time. The endobiotic lingulates were also symbionts of tabulate corals in the Katian of Estonia. Bryozoans hosted the most diverse fauna of endobionts in the Katian of Baltica. Corals and stromatoporoids hosted just few groups of endobionts in the Katian of Baltica.
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