The fish swimming trace Undichna unisulca from the Silurian of Sweden: probably the oldest vertebrate locomotion trace fossil

The fish swimming trace Undichna unisulca is reported from a sandstone block collected from the Upper Silurian (Ludlow) Burgsvik Formation of Gotland, Sweden. It represents the oldest record of a vertebrate trace (apart from coprolites), predating previous finds from the Lower Devonian by at least 10 Ma. A thelodont or acanthodian fish may have produced the sinusoidal trails with the aid of their caudal or anal fins while browsing slowly over the sediment whilst searching for food.     

Intrastratal trace fossil zonation,Cretaceous flysch of northern California

Dissection of fine‐grained turbidites within the Franciscan complex at Trinidad Harbor reveals intrastratal zonation of biogenic structures. The pre‐depositional association comprises only three ichnotaxa (preserved in convex hyporelief) and is less diverse than the tiered post‐depositional association (comprised by at least seven ichnotaxa preserved in full relief). The latter association is dominated by Melatercichnus (n. ichnogen.). Post‐depositional trace‐makers exploited abundant plant detritus deposited with the turbidite sand. Temporal alternation of trace fossil associations resulted from the infrequent, but catastrophic, disturbance of pre‐turbidite communities and local replacement by assemblies of opportunistic organisms. Although probably short‐lived at specific sites, the post‐turbidite infauna was tiered, enabling a variety of deposit feeders to harvest phytodetritus of varied size or density simultaneously at different depths within newly deposited turbidite sand layers.     

The trace fossil Thalassinoides from the Upper Ordovician of Tuva

Traces of Thalassinoides (the tunnels of unknown burrowing organisms) are described from carbonates of the Khondelensky layers of the Upper Ordovician of Tuva. Hitherto, this fossil was unknown in the Ordovician of the USSR. They demonstrate great similarity with Thalassinoides from coeval deposits of the Great Basin, USA. The traces are assumed to have been made in terrigenous-carbonate sediments deposited on the areas of a gently sloping shelf in quiet water, below wave base. □ Upper Ordovician, terrigenous-carbonate sediments, burrows.     

The gonorynchiform fish Dastilbe from the lower Cretaceous of Brazil

We examine the preservation, autecology and morphological variation for several characters of the Cretaceous gonorynchiform fish Dastilbe from the Lower Cretaceous of Brazil and Africa. More than 83 specimens were examined. We test species validity using characters of the caudal endoskeleton and meristic counts of fin-rays vs length. Evidence provided by fossilized soft tissues and slabs containing large individuals 'freeze framed' in the process of swallowing smaller prey meals, show that Dastilbe was predatory, at least as adults, as well as cannibalistic. Dastilbe was probably an anadromous fish tolerant of hypersalinity and in Araripe was subjected to frequent mass mortality events. Observations of the otic region indicate that the lagenar statolith is consistently larger than the saccular statolith, hence revealing a primitive actinopterygian condition. For the first time, a lagenar statolith from Dastilbe has been cleaved to expose putative annuli-like ridges. Our results clearly show that there is a wide degree of morphological plasticity of the endoskeleton coupled with wide meristic variation, and as such, overall length, fin-ray count and even absence or presence of caudal diastema are not suitable criteria for species recognition in Dastilbe . New specimens from the Crato Formation (Aptian) and statistical tests suggest rejection of all species of Dastilbe erected subsequent to Jordan (1910). All Brazilian specimens of Lower Cretaceous Dastilbe can be assigned to the single species D. crandalli Jordan. The African D. batai Gayet is also placed within D. crandalli     

Triuridaceae fossil flowers from the Upper Cretaceous of New Jersey

We report here on a series of fossil flowers exhibiting a mosaic of characters present in the extant monocot family Triuridaceae. Phylogenetic analyses of morphological data from a broad sample of extant monocots confirm the affinities of the fossils with modern Triuridaceae. The fossil flowers were collected from outcrops of the Raritan Formation (Upper Cretaceous, ～90 million years before present), New Jersey, USA. These are the oldest known unequivocal monocot flowers. Because other reports of "earliest" monocots are all based on equivocal character suites and/or ambiguously preserved fossil material, the Triuridaceae fossils reported here should also be considered as the oldest unequivocal fossil monocots. Flowers are minute and unisexual (only male flowers are known); the perianth is composed of six tepals, lacking stomata. The unicyclic androecium is of three stamens with dithecal, monosporangiate, extrorse anthers that open by longitudinal slits. The endothecium has U-shaped type thickenings. Pollen grains are monosulcate. The triurid fossil flowers can be separated into three distinctive species. On the basis of phylogenetic analyses of morphological characters, the fossil taxa nest within the completely saprophytic achlorophyllous Triuridaceae supporting the interpretation that the extinct plants were also achlorophyllous and saprophytic. If so, this represents the earliest known fossil occurrence of the saprophytic/mycotrophic habit in angiosperms.     

The early evolution of feathers: fossil evidence from Cretaceous amber of France

The developmental stages of feathers are of major importance in the evolution of body covering and the origin of avian flight. Until now, there were significant gaps in knowledge of early morphologies in theoretical stages of feathers as well as in palaeontological material. Here we report fossil evidence of an intermediate and critical stage in the incremental evolution of feathers which has been predicted by developmental theories but hitherto undocumented by evidence from both the recent and the fossil records. Seven feathers have been found in an Early Cretaceous (Late Albian, ca 100 Myr) amber of western France, which display a flattened shaft composed by the still distinct and incompletely fused bases of the barbs forming two irregular vanes. Considering their remarkably primitive features, and since recent discoveries have yielded feathers of modern type in some derived theropod dinosaurs, the Albian feathers from France might have been derived either from an early bird or from a non-avian dinosaur.     

The ultrastructure of fossil dispersed monosulcate pollen from the Early Cretaceous of Transbaikalia,Russia

The general morphology, surface sculpturing, and exine ultrastructure have been studied in dispersed monosulcate pollen from the Early Cretaceous of Transbaikalia, Russia. The pollen grains dominate the palynological assemblage extracted from coal deposits of the Khilok Formation in the Buryat Republic, which also contain ginkgoalean leaves of Baierella averianovii as the only constituent of the assemblage of plant megafossils. The relationship between the pollen grains and ginkgoalean leaves from this autochthonous burial is hypothesised on the basis of taphonomical analysis and palaeobiogeographical data. It is shown that the ectexine of the pollen grains includes a thick solid tectum, a thin granular infratectum and a thin foot layer; the endexine is fine-grained, slightly more electron-dense than the ectexine, and is preserved only in places. The distal aperture is formed by a thinning of the exine. No analogous ultrastructure has been described so far in fossil pollen grains of this morphotype studied ultrastructurally from in situ material. For comparison, we also studied the exine ultrastructure of pollen grains Ginkgo biloba. The fossil pollen is not identical to pollen of extant G. biloba, but shows several significant similarities in the exine ultrastructure, which does not contradict the presumable ginkgoalean affinity of the fossil pollen.     

First record of a fossil bird from the Early Cretaceous of Thailand

We present the first known occurrence of a Mesozoic fossil bird from Thailand. The new specimen is the distal end of a left humerus, from the Early Cretaceous Sao Khua Formation in the Northeast of the country, and testifies to the presence of a medium-sized avian in these non-marine strata. This is also the first Mesozoic bird known from the whole of Southeast Asia. To cite this article: E. Buffetaut et al., C. R. Palevol 4 (2005).     

A fossil feather from the Upper Cretaceous of Kras (Slovenia)

A fossil feather preserved as a carbonised trace is described from the Tomaj Limestone at Kri , in the Kras region of southwestern Slovenia. The Tomaj Limestone is a platy and laminated limestone with cherts, which occurs within a well-bedded rudist limestone of the Santonian–Campanian Lipica Formation. It was deposited in a lagoon environment and has yielded a diverse fossil assemblage. Whether this feather belonged to a bird or to a dinosaur is unclear, but it is an addition to the scanty record of Late Cretaceous feathers, from a palaeobiogeographically interesting area.     

The infaunal echinoid Micraster: Taphonomic pathways indicated by sclerozoan trace and body fossils from the Upper Cretaceous of northern Spain

Micraster echinoid fossils are common in the Upper Cretaceous Olazagutía Formation of northern Spain. Tests frequently record sclerobiont signatures (including bioerosion and encrustation), left by reaction and/or coaction phenomena. Among bioerosion structures, Oichnus simplex, O. paraboloides, O. ichnosp. A, Trypanites solitarius, Rogerella ichnosp. indet., Centrichnus cf. eccentricus, Maeandropolydora ichnosp. indet. and fungal microborings are found, as well as pits and fractures. As for sclerozoan body fossils, bivalves (Dimyidae, Anomiidae, Plicatulidae and other Pectinacea), polychaete annelids (serpulids and spirorbids), lituolid foraminiferans (Haddoniidae and Coscinophragmatidae) and bryozoans (cheilostomate ones and others undetermined), as well as other less common groups, have been identified. Taphonomic paths followed by Micraster tests are analysed, based on conservation state and degree of colonisation and sedimentary filling. This allows to distinguish between accumulated fossils and non accumulated ones (including resedimented and reelaborated ones).     

The trace fossil Sinusichnus from the Upper Ordovician of Anticosti Island,eastern Canada

Branched, sinusoidal burrows assigned to Sinusichnus cf. seilacheri Knaust et al. 2016; occur in Upper Ordovician (Hirnantian) carbonates on Anticosti Island. These are abundant and monospecific at the base of the Oncolite Bed of the uppermost Ellis Bay Formation, marking a regional discontinuity surface during the multiphase Ordovician mass-extinction event. In contrast to Mesozoic and Cenozoic records of Sinusichnus, commonly attributed to the activity of decapod and isopod crustaceans, the burrow systems from Anticosti Island were probably produced by other arthropods of unknown affinity. A combined dwelling, locomotion and feeding behaviour of their trace maker is assumed. This is the oldest record of the ichnogenus Sinusichnus, previously only known since the Triassic, and its first evidence from North America.     

A new chimaeroid fish from the Cretaceous of Lebanon

A new species of chimaeroid, Harriotta lehmani, is described. It differs from Recent species of Harriotta in the shape of the paired rostral cartilages and second dorsal fin. This is the first record of a chimaeroid from the Cretaceous fish-beds of Lebanon, as well as being the first fossil representative of the genus Harriotta.     

The oldest human fossil in Europe,from Orce (Spain)

The Orce region has one of the best late Pliocene and early Pleistocene continental paleobiological records of Europe. It is situated in the northeastern sector of the intramontane Guadix-Baza Basin (Granada, Andalusia, southern Spain). Here we describe a new fossil hominin tooth from the site of Barranco León, dated between 1.02 and 1.73 Ma (millions of years ago) by Electron Spin Resonance (ESR), which, in combination with paleomagnetic and biochronologic data, is estimated to be close to 1.4 Ma. While the range of dates obtained from these various methods overlaps with those published for the Sima del Elefante hominin locality (1.2 Ma), the overwhelming majority of evidence points to an older age. Thus, at the moment, the Barranco León hominin is the oldest from Western Europe.     

Terpenoid composition of three fossil resins from Cretaceous and Tertiary conifers

The terpenoid composition of three fossil resins from macrofossils of Cretaceous and Tertiary conifers has been analyzed by gas chromatography–mass spectrometry (GC–MS). The mono-, sesqui- and diterpenoids which have been identified in the resin extracts are derived from precursors produced by the respective source plants and may be used as chemosystematic markers when compared with terpenoids in extant conifers. Sesquiterpenoids (cedrene, cuparene, cadinanes) and phenolic diterpenoids (ferruginol and derivatives) are the major components in Cupressospermum saxonicum Mai (Miocene). The terpenoid characteristics strongly support a relationship to the Cupressaceae s. str. The resin of Doliostrobus taxiformis (Sternberg) Kva ek (Eocene) consists of abietane and pimarane type resin acids accompanied by minor amounts of phenolic diterpenoids (ferruginol, hinokiol). According to morphological and anatomical characteristics, D. taxiformis was previously compared to both, extant Araucariaceae and Cupressaceae s.l., but the terpenoid pattern of the resin now supports a relationship to the Cupressaceae s.l. rather than to Araucariaceae. Degraded diterpenoids of the abietane type are the major compounds in the extract of Tritaenia linkii (Roemer) Mägdefrau et Rudolf (Lower Cretaceous) indicating considerable oxidative alteration of the resin. Since the terpenoids in the resin of T. linkii are highly degraded or belong to the common abietane class, the leaves cannot be assigned or compared to any modern family based on their terpenoid composition. The presence of ferruginol probably excludes pinaceous affinities. Terpenoids proved to be valuable chemosystematic markers for fossil conifers once they are adequately preserved. The analysis of resin extracts by GC–MS is a suitable tool for the investigation of soluble compounds in fossil plants.     

A fossil brain from the Cretaceous of European Russia and avian sensory evolution

Fossils preserving traces of soft anatomy are rare in the fossil record; even rarer is evidence bearing on the size and shape of sense organs that provide us with insights into mode of life. Here, we describe unique fossil preservation of an avian brain from the Volgograd region of European Russia. The brain of this Melovatka bird is similar in shape and morphology to those of known fossil ornithurines (the lineage that includes living birds), such as the marine diving birds Hesperornis and Enaliornis, but documents a new stage in avian sensory evolution: acute nocturnal vision coupled with well-developed hearing and smell, developed by the Late Cretaceous (ca 90Myr ago). This fossil also provides insights into previous 'bird-like' brain reconstructions for the most basal avian Archaeopteryx--reduction of olfactory lobes (sense of smell) and enlargement of the hindbrain (cerebellum) occurred subsequent to Archaeopteryx in avian evolution, closer to the ornithurine lineage that comprises living birds. The Melovatka bird also suggests that brain enlargement in early avians was not correlated with the evolution of powered flight.     

Isopodichnus in a trace fossil assemblage from the Old Red Sandstone

Isopodichnus stromnessi sp. nov. from the Lower Stromness Flags of Orkney is described in detail, and the range of variation in the traces ascribed to different habits of different sized individuals producing the traces. Activity diagrams illustrate scme of the burrowing habits of the organism. Isopodichnus is typical of non-marine strata, particularly those of shallow impermanent lacustrine environments, and can be distinguished from Cruziana on the basis of the shape of the trace ending. AsSociated burrows are briefly described and indicate the presence of a hitherto undescribed invertebrate fauna associated with the Orcadian flagstone sequence of the Middle Old Red Sandstone.     

Ethological analysis of the trace fossil Zoophycos: hints from the Arctic Ocean

Löwemark, L. 2011: Ethological analysis of the trace fossil Zoophycos: Hints from the Arctic Ocean. Lethaia, Vol. 45, pp. 290–298. The distribution of the trace fossil Zoophycos in Quaternary marine sediments from the Arctic Ocean was studied in twelve piston and gravity cores retrieved during the Swedish icebreaker expeditions YMER80, Arctic Ocean‐96 and LOMROG I & II. The sampled cores span an area from the Makarov Basin to the Fram Strait. Zoophycos was only found in two cores taken at more than 2 km water depth on the slope of the Lomonosov Ridge, but was absent in cores obtained at shallower depth, confirming earlier observations of the trace maker’s bathymetric preferences. The two cores containing Zoophycos are characterized by quiet sedimentation and slightly enhanced food flux compared with the general Arctic. The occurrence of Zoophycos in these cores in a setting that is characterized by extreme seasonal variations in food flux due to the total ice coverage during winters and high primary productivity during the long summer days, is interpreted to be a cache‐behaviour response to pulsed flux of food to the benthic realm. □Arctic Ocean, ethology, Quaternary, spreiten, trace fossils, Zoophycos.     

Two new fossil flowers of magnoliid affinity from the Late Cretaceous of New Jersey

Two taxa of cupulate magnoliid fossil flowers, Cronquistiflora and Detrusandra, are described from the Late Cretaceous (Turonian, ∼90 million years before present [MYBP]) Raritan (or lower Magothy) Formation of New Jersey. The fossil taxa are represented by flowers at various stages of development, associated fragments of cup-shaped floral receptacles with attached anthers, and isolated anthers. Both taxa have laminar stamens with adaxial thecae and valvate dehiscence. Pollen is boat-shaped and foveolate in anthers associated with Cronquistiflora and spherical with reticulate ornamentation in Detrusandra. Cup-shaped receptacles are externally bracteose in both taxa. The receptacle of Cronquistiflora is broader than the campanulate one of Detrusandra. Cronquistiflora also has more carpels (∼50 in a spiral vs. ∼5 in a whorl or tight spiral). In Detrusandra the carpels are surrounded by dorsiventrally flattened structures (pistillodes?) that are remote from the attachment of the stamens near the distal rim of the receptacular cupule. Detrusandra stigmas are rounded and bilobed, while those of Cronquistiflora, although bilateral in symmetry, are somewhat peltate. The fossil taxa share prominent characters with extant cupulate magnoliids (e.g., Eupomatia, Calycanthus), but also share characters with other magnoliids including Winteraceae. These fossils represent taxa that are character mosaics relative to currently recognized families. Inclusion of these fossils in existing data matrices and ensuing phylogenetic analyses effect changes in tree topologies consistent with their mosaicism relative to modern taxa. But such analyses do not definitively demonstrate the affinities of the fossils other than illustrating that these fossils are generalized magnoliids. Additional analysis of modern and fossil magnoliids is necessary to fully appreciate the phylogenetic significance and positions of these fossil taxa. However, the results of the phylogenetic analyses do introduce the possibility that extinct taxa of Magnoliales with cupulate floral receptacles were transitional between basal angiosperms and those with tricolpate pollen. The fossils provide insights into the timing of evolution of character complexes now associated with coleopteran pollination.