Oligocene Shorebird Footprints,Kandi, Ombilin Basin,Sumatra

Recent fieldwork in the Ombilin Basin of west-central Sumatra resulted in the discovery of two distinct types of avian footprints, both referable to the ichnogenus Aquatilavipes. The footprints were discovered in the Oligocene Sawahlunto Formation in a creek side outcrop near the Kandi Ombilin Mine. Aquatilavipes wallacei is a small species of Aquatilavipes (～ 19 mm wide; 27 mm long) with elongate third digits, wide total divarication angles (120–150°) and inwardly curved peripheral digits. Aquatilavipes ichnospecies A are also small traces (average 21 mm wide; 31 mm long) with elongate third digits and straight to slightly outwardly curved peripheral digits. These traces are similar in morphology to those of small modern shorebirds such as rails (Rallidae), sandpipers (Scolapacidae) or plovers (Charadriinae).

The Sawahlunto traces occur in very fine-grained to fine-grained sandstone characterized by low-relief current ripples, many of which exhibit mud-draping. A low diversity invertebrate trace fossil assemblage consisting of Arenicolites, Diplocraterion, Planolites, Monocraterion, Skolithos and Coenobichnus co-occurs with the bird footprints. This succession is interpreted as intertidal sand flats. Probe and peck marks preserved on the same bedding planes as the bird footprints support the interpretation that these birds occupied the Kandi intertidal flats for foraging purposes.     

First report of fossil turtle eggshell west of the Colorado Plateau

The first fossil turtle eggshell from North America west of the Colorado Plateau (UCMP 218504) is described, adding to the growing global record of chelonian eggshell. Ten blocks of mudstone were collected from the Upper Miocene (Clarendonian) Orinda Formation, Contra Costa County, California, during the excavation of the Caldecott Tunnel Fourth Bore. They contain rigid eggshell averaging 500 μm in thickness. Closely packed shell units with a height/width ratio of 2:1 are composed of radiating, acicular crystals originating from a basal core, a set of characters that support the identification of the eggshell as chelonian, and further as testudinoid. Egg diameter is estimated at between 34.2 and 42.4 mm based on shell curvature. Adult carapace length is estimated to be 70.7 cm, a size similar to fossils of Hesperotestudo known from California and present in the Orinda Formation. UCMP 218504 greatly extends the geographic record of turtle fossil eggshell and adds to the limited number of mid-Neogene eggs. It also provides evidence for a warm climate in Miocene California and demonstrates the south-eastern contraction of conditions appropriate for tortoise reproduction during the last 10 million years.     

Evidence for targeted elasmobranch predation on thalassinidean shrimp in the Miocene Taliao Formation,NE Taiwan

Terrestrial and marine invertebrate organisms both leave records of their activities in the sediment in the form of trace fossils, at least during certain stages of their ontogeny. In contrast, trace fossils produced by vertebrate organisms are scarce, although terrestrial trace fossils provide exclusive insights into the social behaviour of their producers. In the marine realm, vertebrate trace fossils are relatively rare, difficult to identify and problematic to interpret. However, in certain settings, observations on serendipitously preserved and exposed trace fossils can shed light on the predatory behaviour of marine vertebrates. In Miocene outer shelf to nearshore sandstones of the Taliao Formation in NE Taiwan, large numbers of bowl‐shaped trace fossils can be observed. Morphology and size range (diameter typically 10–30 cm, average depth around 10 cm) of these trace fossils agree well with feeding traces of modern stingrays, and the trace fossil Piscichnus waitemata, which has been attributed to bottom feeding rays. Stingrays direct a jet of water from their mouths to excavate a bowl‐shaped pit to expose their prey. In the material filling the excavated bowl, broken pieces of two other common trace fossils, Ophiomorpha and Schaubcylindrichnus, are often found, and in a number of cases, vertical shafts of Ophiomorpha surrounded by dispersed pieces of wall material have been observed. In contrast, surrounding sediment rarely contains this kind of broken pieces of wall material. These observations clearly indicate that stingrays specifically targeted the producers of the trace fossils: thalassinoid crustaceans and worms, respectively. The targeted predation of these relatively deep burrowers furthermore suggests that the rays used their electroreceptive organs to locate the prey; as such, direct targeting of buried prey only based on olfactory senses has been shown to be ineffective in experiments with extant myliobatiform rays.     

Ichnology of Lower Jurassic beach deposits in the Shemshak Formation at Shahmirzad,southeastern Alborz Mountains,Iran

A 19 m thick package of well-sorted lowermost Jurassic (Hettangian-Lower Sinemurian?) sandstones within the Shemshak Formation of the southeastern Alborz Mountains displays features characteristic of foreshore to upper shoreface environments such as tabular bedding, low-angle lamination, trough cross-stratification, parting lineation, and oscillation ripples. In contrast to most other beach successions recorded in the literature the sandstones contain a trace fossil assemblage characterised by low abundance but comparatively high diversity. The assemblage, comprising 14 ichnotaxa, is dominated by Palaeophycus heberti, Rhizocorallium irregulare, Gyrochorte comosa, and Parahaentzschelinia surlyki. Contrary to predictions, which assume a dominance of suspension-feeders in such high-energy environments, the trace fossil assemblage represents a variety of ethological groups ranging from suspension-feeders to deposit-feeders, detritus-feeders, scavengers, and a possible trap constructor (Ctenopholeus), whereby deposit-feeders predominate. This anomaly is explained by a high amount of organic detritus in the sediment, indicated by abundant plant material, and a position of the beach in the vicinity of a river mouth.     

Scolicia and its producer in shallow-marine deposits of the Miocene Chenque Formation (Patagonia,Argentina): functional morphology and implications for understanding burrowing behavior

Abstract

Scolicia is one of the most conspicuous trace fossils in lower shoreface deposits of the Miocene Chenque Formation of Patagonia, Argentina. This ichnotaxon consists of horizontal, sinuous or meandering trace fossils with a laminated backfill and two parallel strings located at the base. Abundant body fossils attributed to Brisaster iheringi occur in close association to these trace fossils. The echinoids are very well preserved, and most of the specimens have some areas with their spines attached in life position. In particular, preservation of the subanal tufts of spines, associated to isopores (which are interpreted as being associated to funnel building tube feet), supports the interpretation that these organisms are the producers of Scolicia isp. A shaft connecting the burrow with the sediment-water interface was not observed in vertical sections of the excavations, although on bedding plane surfaces, some small circular tube outlets are recognized. However, the great diversity and abundance of ichnofossils co-occurring in these deposits may preclude adequate identification of vertical structures. These deposits provide an excellent opportunity to integrate trace fossil data, body fossil information and observations from modern analogues in order to perform a morpho-functional analysis of Scolicia.     

Miocene bristlemouths (Teleostei: Stomiiformes: Gonostomatidae) from the Makrilia Formation,Ierapetra, Crete

Bristlemouths of the genus Cyclothone are currently regarded as the most abundant vertebrates on Earth. The fossil record seems to suggest that these fishes diversified during the Miocene in the Pacific Ocean, but there is no evidence of their presence in the Miocene of the Atlantic Ocean and Mediterranean basin. A new bristlemouth, Cyclothone gaudanti sp. nov. (Teleostei, Stomiiformes, Gonostomatidae), is described herein based on 16 specimens from the Upper Miocene Makrilia Formation (late Tortonian of Crete, Greece). The small sized species is characterized by light pigmentation, 30–31 (14–15 + 15–16) vertebrae, dorsal fin with 10–13 rays, anal fin with 10–14 rays, premaxilla bearing seven closely spaced teeth, maxilla with 42–55 teeth, epipleurals, and autogenous parhypural. The presence of epipleurals appears to be unique of this Miocene species, and the re-establishment of this ancestral character state may be possibly interpreted as related to a phylogenetic character reversal. Morphological and paleoecological considerations suggest that this species possibly inhabited the upper mesopelagic layer, at depths ranging from 2–300 and 500 meters.     

The earliest fossil evidence of bone boring by terrestrial invertebrates,examples from China and South Africa

We report the oldest fossil evidence of osteophagia by terrestrial invertebrates on both the Asian and African continents. Bones attributable to the Middle Jurassic dinosaur Chuanjiesaurus (Dinosauria: Sauropoda) were found with post-mortem insect modification in the Chuanjie Formation, Yunnan Province, China. The morphology of the borings closely matches the ichnogenus Cubiculum. Based on the lack of bioglyphs observed in Cubiculum ornatus, a new ichnospecies is proposed here. The new trace fossil, Cubiculum inornatus isp. nov., is interpreted to have been constructed for pupation by an unknown taxon of insect. Additionally, we report even older borings from Early Jurassic dinosaur bones of the Elliott Formation in the Karoo Basin, which represent the second oldest occurrence of insect traces in bone from continental settings. Both trace fossils sites have palaeogeographic implications for the origins and dispersal of osteophagia amongst terrestrial invertebrates during the Mesozoic. These discoveries push back the antiquity of pupation in animal bones by more than 100 million years to the Middle Jurassic, indicating that this behaviour, and osteophagy more generally, originated early in the Mesozoic, roughly comparable with the origination of insect pupation in woody substrates (Late Triassic).     

The trace fossil Circulichnis as a record of feeding exploration: New data from deep-sea Oligocene–Miocene deposits of northern Italy

Circulichnis is a puzzling, ring-like trace fossil preserved on bedding planes. It is represented mostly by its type ichnospecies C. montanus, which is characterized by an evenly circular or elliptical course. A new ichnospecies, C. ligusticus, is distinguished based on material from deep-sea Oligocene–Miocene deposits of the Tertiary Piemonte Basin, NW Italy. It shows a winding or irregular course. A new model of Circulichnis is proposed as an exploration burrow produced mostly by the trace makers of Helminthoidichnites, Gordia, or Helminthopsis, as it moved to a different sediment layer to checking its feeding utility. This type of behaviour occurred already by the Ediacaran and is common in marine, mostly deep-sea bedded sediments. The trace makers belong mostly to polychaetes in marine sediments and to oligochaetes in continental sediments.     

Fossil record of a silurid catfish from the Middle Miocene Sanuki Group of Ohkawa, Kagawa Prefecture, Japan

A fossil specimen identified as a silurid catfish (92.5 mm SL) was collected from the Middle Miocene Sanuki Group (15.8±0.9 Ma) of Ohkawa, Kagawa Prefecture, Japan. This is the oldest certain record of a silurid catfish. Morphological characteristics of the specimen are as follows: 52 or 53 vertebrae, 61 or 62 anal fin rays, a stout, short spine (11%SL) and 10 or more soft rays of the pectoral fin, 8 or more pelvic fin rays, 8 or more branchiostegal rays, head length of ca. 24%SL, and most probably not forked caudal fin. The fossil specimen is clearly distinct from three extant silurids in Japan, and probably belongs to an undescribed form considering its geological age.     

Rosselia socialis: a dwelling structure of a probable terebellid polychaete

The trace fossil Rosselia socialis Dahmer 1937 is a funnel-shaped structure characterized by a concentrically laminated wall having a narrow cylindrical shaft at the central portion. In association with well-preserved funnel-shaped R. socialis , many spindle-shaped R. socialis -like specimens are abundant in the Middle Pleistocene Kongochi Formation in central Japan. While the former always occur just below an erosional bedding plane or outcrop surface parallel to the bedding, the latter are found in sediment showing no breaks in sedimentation. This suggests that the funnel-shaped 'R. socialis' is actually the truncated lower part of the spindle-shaped structure. In one specimen, deformation of laminae appears to have formed synchronously with construction of the wall. Morphology of the structure strongly suggests that the wall of R. socialis was formed through outward expansion caused by accretion of muddy material at the inner surface of the wall by the trace-maker inhabiting the central burrow. A specimen that was covered by a volcanic ash has the wall made up of the ash. This indicates that the maker of the burrow utilized surface sediment to construct the wall; that is, the trace-maker was possibly a detritus feeder. The terebellid polychaetes are reasonable candidates for the trace-makers. □ R osselia socialis , Japan, Middle Pleistocene, trace fossil, trace-making process, trace-maker.     

A new genus and species of fossil myliobatoid ray from the Fishburne Formation (lower Eocene/Ypresian) of Berkeley County,South Carolina,USA

Elasmobranch fossils recovered from the Fishburne Formation (lower Eocene/Ypresian) of Berkeley County, South Carolina, USA, include species from four genera of sharks and six genera of rays. Of particular interest was the recovery of multiple isolated teeth from a new genus and species of the cownosed ray family Rhinopteridae, which is the focus of this study. The unique crown morphology separates this genus and species from Rhinoptera. Eorhinoptera grabdai, gen. et sp. nov., is represented by small, bar-shaped teeth in the shape of greatly elongated hexagons. These teeth are the isolated elements of a dental plate. The holotype, with 12 wide root lobes, is the most elongated in the sample being 1 cm long and 1.5 mm wide, indicating an origin in the central region of the plate. Paratypes are less elongated, have 4–8 root lobes and are from more lateral rows. The crown is smooth and has a distinctly convex occlusal surface. Eorhinoptera is only the second genus of cow-nosed ray. Its distinctive crown morphology may have allowed it to exploit different kinds of prey than those favoured by rays that lacked convex tooth crowns.     

Lower Jurassic Arthropod Resting Trace from the Hartford Basin of Massachusetts,USA

Cheliceratichnus lockleyi ichnogen. nov. et ichnosp. nov. is a new ichnotaxon of arthropod resting trace (cubichnium) from the Lower Jurassic (Hettangian) East Berlin Formation in Holyoke, Massachusetts, USA. The trace fossil is preserved as showing many of the external anatomical features of the exoskeleton, which resemble those of some chelicerates, notably sun spiders (Solifugae). The resting trace is directly associated with a trackway of the ichnospecies Acanthichnus cursorius Hitchcock. This is the first described fossil resting trace of a solifugan-like arthropod, and the first direct evidence of a trackmaker of A. cursorius.     

The first named Ediacaran body fossil, Aspidella Terranovica

Aspidella terranovica Billings, 1872 was first described from the late Neoproterozoic Fermeuse Formation (St. John's Group) on the Avalon Peninsula of eastern Newfoundland, approximately 1km stratigraphically above the famous Ediacaran biota at Mistaken Point, and several kilometres below the base of the Cambrian. Aspidella has been reinterpreted perhaps more than any other Precambrian taxon, and has variously been regarded as a fossil mollusc or ‘medusoid’, a gas escape structure, a concretion, or a mechanical suction mark. Our studies indicate that Aspidella includes a wide variety of preservational morphs varying from negative hyporeliefs with a raised rim and ridges radiating from a slit (Aspidella‐type preservation), to flat discs with a central boss and sharp outer ring (Spriggia preservation), to positive hyporeliefs with concentric ornamentation (Ediacaria preservation). Specimens occur in a continuum of sizes, with preservational styles dependent on the size of the specimen and the grain size of the host lithology; the elongation of specimens is tectonic. Aspidella is confirmed as a body fossil from observations of complex radial and concentric ornamentation, mutually deformed borders in clusters of specimens, and occurrence on the same bedding planes as certain distinctive Ediacaran taxa. Aspidella is indistinguishable from, and has priority over, several of the most common genera of late Neoproterozoic discoidal body fossils worldwide. Similar fossils from Australia are interpreted as holdfasts of frond‐like organisms. The density of specimens in the Aspidella beds suggests levels of benthic biomass in the Neoproterozoic that could rival those of modern marine communities. The serial growth forms, PalaeopascichnusIntrites, Neonereites renariusYelovichnus, associated with Aspidella, are interpreted as body fossils of unknown affinities rather than trace fossils. A new, trilobed, Ediacaran body fossil, Triforillonia costellae gen. et sp. nov., is described from the Aspidella beds of the Fermeuse Formation.     

New Pliocene remains of Camelus grattardi (Mammalia,Camelidae) from the Shungura Formation,Lower Omo Valley,Ethiopia, and the evolution of African camels

Abstract

Camels are exceptionally rare in the Plio-Pleistocene fossil record of Africa, hindering attempts to understand the evolution of this family on the continent. Here we describe recently collected camel specimens from the Shungura Formation, Lower Omo Valley, Ethiopia, and attribute these remains to Camelus grattardi. The new specimens date to the late Pliocene (~3 to 2.6 Ma) and consist of three upper molars, one upper premolar, and two proximal metatarsals. The dental specimens confirm this species’ small P4 relative to its molars, a trait that differs significantly from all extant and fossil Old World camels. The metatarsals indicate that C. grattardi was similar in size to the living Bactrian camel, C. bactrianus. Phylogenetically, we find no suitable ancestor, sister, or descendant of the eastern African fossil camel, which suggests greater lineage diversity in Plio-Pleistocene Camelus than previously recognised. Microwear analyses suggest that C. grattardi was likely a mixed-feeder preferring browse, which is consistent with carbon isotopes of enamel from the Turkana Basin. A review of the fossil record of African camels suggests no clear paleoenvironmental association, as fossil camels occur in a range of environments from dry savannas with no permanent water bodies to closed woodlands along the paleo-Omo River.     

Fossil roots with root nodules from the Madygen Formation (Ladinian–Carnian; Triassic) of Kyrgyzstan

Documented evidence of root nodules in fossil plants is exceedingly rare, and thus the evolutionary history and paleobiology of these specialized structures hosting symbiotic microorganisms continue to be largely unresolved. Here we report adpression fossils of slender roots from the ~237-million-yr-old Madygen Formation in Kyrgyzstan, to which are laterally attached spheroidal protuberances up to 2.5 mm in diameter that we interpret as root nodules based on spatial arrangement and comparisons with other fossil and extant root nodules, along with several types of other plant structures exhibiting a superficially similar appearance (e.g., fertile organs, rhizome tubers). The producer of the roots and the biological nature and affinities of the microorganisms inhabiting the nodules remain unknown. The Madygen fossils are nevertheless significant because they represent the second-oldest record of root nodules worldwide, predated only by permineralized mycorrhizal root nodules from the Triassic of Antarctica.     

The Trace Fossil Diplopodichnus from the Lower Jurassic Lacustrine Sediments of Central China and the Isopod Armadillidium vulgare (Pillbug) Lebensspuren as its Recent Analogue

The trace fossil Diplopodichnus isp. was identified in lacustrine siliciclastics of the Lower Jurassic Anyao Formation in the Henan Province, central China. This is the youngest occurrence of this ichnogenus. It is similar to some variants of recent surface traces of the isopod Armadillidium vulgare (pillbug) crawling on soft mud in temporal puddles. Therefore, isopods are suggested to be producers of the described Diplopodichnus isp. It seems that isopods should be taken into account as important component of deep lacustrine ecosystems by the Early Jurassic.     

First Report: Trace Fossil Assemblage Ptychoplasma (P. excelsum,P. vagans), Dendroidichnites (D. irregulare), Ctenopholeus (?C. kutcheri) and Bergaueria (B. hemispherica) in the Cretaceous Rocks of Bagh Formation,Mainland Gujarat,India

Abstract

This report documents the discovery of repichnia trace fossils Ptychoplasma (P. excelsum and P. vagans) and Dendroidichnites (D. irregulare); the fodichnia traces ?Ctenopholeus (?C. kutcheri) and cubichnia traces Bergaueria (B. hemishperica) from silty limestones of the Cretaceous Bagh Formation. These trace fossils have significant implications for the depositional facies and the paleo-environmental interpretations of the Bagh Formation, which have long been debated. Previously identified traces of Protovirgularia were also found in association with the newly discovered trace fossils, indicating the coexistence of both wedge and cleft-foot bivalves. The western area of the mainland Gujarat is known for its abundance and diversity of trace fossils. The trace fossil bearing Cretaceous rocks in the region occur as thin irregular detached patches and linear outcrops. Previous studies documenting trace fossil assemblages from the Bagh Formation characterised them as a combination of dwelling, feeding and locomotion forms, with the stratigraphic unit becoming less fossiliferous westward. Trace fossils in this formation have been studied and described by many workers in the surrounding areas; however, ichnofossils described in this study are new to the Bagh Formation in this area. These trace fossils were observed on recently exposed outcrops along road cuts associated with new road construction from Khasra to Mogra village around Kadipani in Mainland Gujarat.     

Lunulichnus Tuberosus Ichnogen. and Ichnosp. Nov. from the Early Eocene Wasatch Formation,Fossil Butte National Monument,Wyoming: An Arthropod-Constructed Trace Fossil Associated with Alluvial Firmgrounds

A new trace fossil, Lunulichnus tuberosus, is described from fluvial deposits of the Wasatch Formation (early Eocene) at Fossil Butte National Monument, southwestern Wyoming, USA. L. tuberosus are straight, vertical to obliquely oriented, unlined cylindrical burrows with pronounced crescent-shaped wall sculptings. In situ examples of these trace fossils are most commonly preserved as sand-filled casts emanating from the erosional bases of fluvial channel sandstone bodies into underlying floodplain mudstone/siltstone beds. L. tuberosus is interpreted as the dwelling trace of a stream-dwelling decapod crustacean. Excellent preservation of fine detail, particularly their diagnostic crescent-shaped wall sculptings, support the hypothesis that L. tuberosus were excavated in firm substrata subjacent to fluvial erosional surfaces. As such, they are interpreted as constituents of alluvial Glossifungites trace fossil assemblages.     

A fossil earthstar (Geasteraceae; Gasteromycetes) from the Late Cenozoic of Puebla,Mexico

The compressed basidiocarp of a fungus belonging to Geasteraceae (Lycoperdales; Gasteromycetes) was recovered from the plant-bearing Cenozoic strata of the Pié de Vaca Formation, Puebla, Mexico. The fossil specimen consists of an open exoperidium with ten triangular rays, and a central, circular endoperidium with an eccentrical ostiole and irregular surface relief. Scanning electron microscopy revealed a delicate reticulum on the surface of rays and on samples of the endoperidium. An acetolyzed fragment of the endoperidium yielded a few fungal spores, and similar spores were also obtained from an acetolyzed rock fragment adjacent to the fossil specimen. The fossil fungus exhibits the characteristics of extant earthstars; morphological comparison between the extant and the fossil earthstar and the type of spores obtained from the endoperidium of the latter indicate its affinity with Geastrum, although uncertainty in diagnostic characters preclude its assignment to a living species. The report of a complete basidiocarp of Geastrum from the Cenozoic of Puebla may contribute greatly to the knowledge about the spatial distribution and evolutionary history of Geasteraceae and Lycoperdales.