Devonian Fish Research Articles

The Early Devonian Xitun Vertebrate Fauna in South China inhabited a shallow marine environment with changing salinity

The Early Devonian Xitun Vertebrate Fauna, represented by early members of crown sarcopterygians, such as Youngolepis , Diabolepis , Psarolepis , Achoania and Styloichthys , is mainly hosted in the Xitun Formation in the Qujing area, East Yunnan of China. Despite numerous research articles describing taxa from this famous Lochkovian fauna and its sedimentary and tectonic environments, there is no objective and coherent interpretation of the palaeoenvironment in which these early vertebrates lived. Based on detailed field geological investigation in recent years in the surrounding areas of Qujing City and measurements from the Xitun Formation section, this paper focuses on the analysis of some geochemistry indices of major, trace and rare earth elements to accurately elucidate the sedimentary environment of the Xitun Formation and deepen our understanding of the relationship between Early Devonian fishes and the environment. The analyses of the sensitive geochemistry indices of depositional and tectonic settings, sedimentary provenance, weathering, palaeoclimate, palaeosalinity and palaeoredox conditions indicate that the Lower Devonian Xitun Formation in East Yunnan was mainly deposited in a shallow marine setting with three phases of seawater–freshwater influx under a warm and humid climate, and a stable, oxygen-rich condition, which promoted the flourishing of Early Devonian marine fishes. Supplementary material: Data on the major (Table A), trace (Table B) and rare earth (Table C) elements are available at https://doi.org/10.6084/m9.figshare.c.7020642 Thematic collection: This article is part of the Chemical Evolution of the Mid-Paleozoic Earth System and Biotic Response collection available at: https://www.lyellcollection.org/topic/collections/chemical-evolution-of-the-mid-paleozoic-earth-system

Basin and petroleum systems modelling to characterise multi-source hydrocarbon generation: A case study on the inner Moray Firth, UK North Sea

In this paper we used basin and petroleum systems modelling (BPSM) of the Inner Moray Firth, UK North Sea to identify the contributions of different source rocks, mixing ratios of accumulated hydrocarbons, and migration pathways of charging the three known fields in the basin – Beatrice, Jacky and Lybster fields. In this study, model scenarios indicate that extensive faulting is a key control on hydrocarbon migration and accumulation, that the accumulations in the basin do not contain Kimmeridge Clay Formation oil, and that they are mixed in a ratio of ∼65:35 Devonian Fish Bed vs Pentland Formation contribution. Migration modelling suggests that Beatrice Field was charged predominantly by proximally sourced hydrocarbons, whereas Jacky and Lybster fields were charged by a near-even mix of proximal and deep-basin hydrocarbons from the Great Glen Sub-Basin.

НАЧАЛО ИЗУЧЕНИЯ ПАЛЕОЗОЙСКИХ БЕСЧЕЛЮСТНЫХ И РЫБ. ПЕРВЫЕ ШАГИ - ИССЛЕДОВАНИЯ СТЕПАНА СЕМЁНОВИЧА КУТОРГИ (1805-1861)

Agnathans and fishes with massive bone armors were widely spread among the vertebrates in the Early Paleozoic. Their remains were well preserved in fossil state. At present, many species of Devonian agnathans and fishes have been described and studied. Different taxonomic systems have been suggested based on their fossil exoskeletal elements. But in the first part of the nineteenth century, when scientists first came across such remains, their nature was not immediately understood. Discovered remains of armored ichthyofauna were identified as bones of reptiles and amphibians even by outstanding scientists of that time. Professor of the Imperial St. Petersburg University Stepan Semyonovich Kutorga was among them. This article supplies a brief biography of the scientist and an analysis of his works in the formative period of vertebrate paleontology in Russia. S. S. Kutorga was at the origin of the system of monographic descriptions and collections - the most important source of information in fundamental paleontological research. Kutorga’s collection, currently stored at the St. Petersburg State University, is the first monographic collection of Devonian ichthyofauna in our country.

The swimming trace Undichna from the latest Devonian Hangenberg Sandstone equivalent of Morocco

Trace fossils occur in several strata of the Devonian and Carboniferous of the eastern Anti-Atlas, but they are still poorly documented. Here, we describe a fossil swimming trace from strata overlying the Hangenberg Black Shale (correlation largely based on lithostratigraphy; Postclymenia ammonoid genozone, ca. 370 Ma old). We discuss the systematic position of the tracemaker and its body size. This ichnofossil is important for three main reasons: (1) it is considered here to be the first record of Undichna from the Devonian of Gondwana, as far as we know; (2) it is the oldest record of vertebrate trace fossils from Africa; (3) it provides a unique window into the behaviour of Late Devonian fishes for which body-fossils cannot provide direct evidence. Further, we put this discovery into the macroecological context of the palaeoenvironment following the Late Devonian Hangenberg biodiversity crisis.

A new late devonian fish fauna from Northeastern Brazil

ABSTRACT Devonian fishes from South America tend to be fragmentary and sparse, catching little attention for palaeontological sampling. However, some of these remains demonstrate a wide variety of fishes which help understanding environmental and palaeogeographic patterns across the Devonian. In the Parnaíba Basin, the occurrence of Devonian fishes was thought to be restricted to the Pimenteira Formation (Middle Devonian; Eifelian-Givetian). It is described here for the first time fish remains from the Upper Devonian (Famennian) Longá Formation. These fossils represent at least two chondrichthyan (including acanthodians) taxa based on fin spines and a jaw fragment, and osteichthyan taxa based on dermal plates. Although fragmentary, these represent the first Devonian osteichthyan occurrence for the Parnaíba Basin and add to the scares Late Devonian fish record from Brazil. Recent studies have questioned the previous interpretations regarding the relationship between Gondwana and Euramerica, instead supporting more endemic vertebrate communities. Our results reinforce the palaeontological potential of the Palaeozoic strata of the Parnaíba Basin and call for additional work on the region, which may shed light on the diversification of vertebrates across Gondwana.

First occurrence of fossil vertebrates from the Carboniferous of Colombia

Data concerning Paleozoic vertebrates from the South American continent are still scarce. In Colombia, occurrences were until now restricted to the Late Devonian fish assemblage from Floresta and, ...

Late Devonian antiarch remains (placoderm fish) from the Gilberton Formation, north Queensland

New Devonian fish remains are described from the lower part of the Gilberton Formation of north Queensland, the first identifiable specimens found since the original specimen was described in 1936. They include the first determinable dermal skull bones from this deposit. Some dermal bones of the trunk armour are closely associated, and of similar size with morphology consistent with coming from the same fish, permitting a provisional reconstruction of the ventral wall of trunk armour. The new morphological evidence indicates a form close to the antiarch Remigolepis, and a likely age of late Famennian for the lower fossiliferous strata of the Gilberton Formation.

New information on the giant Devonian lobe-finned fish Edenopteron from the New South Wales south coast

Edenopteron, with a lower jaw some 48 cm long, and total length perhaps exceeding 3 m, is the largest Devonian lobe-fin known from semi-articulated remains. New material described from the type locality (Boyds Tower, south of Eden) includes three slightly smaller articulated skulls and jaws, and additional bones of the shoulder girdle. Another articulated skull roof, shoulder girdle and palate is described from a second locality (Hegarty Bay), about 10 km south of Boyds Tower. Both localities represent the upper part of the Worange Point Formation, of late Famennian age (uppermost Upper Devonian). The new morphological evidence supports a close relationship to the tristichopterids Mandageria and Cabonnichthys, from the slightly older (Frasnian, Upper Devonian) fossil fish assemblage at Canowindra, New South Wales. Features of the shoulder girdle (supracleithrum, anocleithrum) suggest that Edenopteron is more closely related to Mandageria than Cabonnichthys. Eight characters are used to define a tristichopterid subfamily Mandageriinae, to which Notorhizodon from the Middle Devonian of Antarctica is also referred. The Mandageriinae is endemic to East Gondwana (Australia–Antarctica). In combination with possibly the most primitive tristichopterid, Marsdenichthys from the Frasnian of Victoria, these distributions implicate East Gondwana as a likely place of origin for the entire group. This relates to the major but unresolved question of a possible Gondwana origin for all the land vertebrates (tetrapods).An endemic Gondwanan sub-group (Mandageriinae) of the Devonian fishes closest to land animals (tetrapodomorph tristichopterids) is confirmed.Retention of primitive features (e.g. accessory vomers) points to an earlier origin of the Mandageriinae in East Gondwana, consistent with the Victorian occurrence of another primitive tristichopterid (Marsdenichthys).Edenopteron is confirmed from a second south coast fossil site, and new characters indicate its closest relative is Mandageria from Canowindra, NSW.Congruent evidence of older Gondwanan occurrences in other groups (basal tetrapodomorphs, rhizodontids, canowindrids), and previously dismissed trace fossil evidence (Grampians trackways), implicate South China and East Gondwana as the likely place of origin for all land vertebrates.

Fish hunting trace Osculichnus and the oldest Sinusichnus sinuosus from the Upper Devonian of South China

Trace fossils are special objects in the study of predator–prey interactions in the fossil record. Here we report on diverse morphological types of the gnathostome fish hunting trace Osculichnus from the Upper Devonian of South China. The studied Osculichnus specimens occur as groups of bilobate mounds on the sole of fine- to medium-grained quartz sandstones from the estuarine-embayment depositional system of the Upper Devonian Wutong Formation in Wuhan city. The fish feeding trace Osculichnus is closely associated with the highly regular, branched sinuous trace Sinusichnus sinuosus on the bedding plane. Previously, Sinusichnus sinuosus has been typically reported from Late Cretaceous to Miocene marginal-marine sediments, with two records in the Lower and Middle Triassic of South China, and is generally regarded as the burrows of decapod crustaceans. The discovery of Sinusichnus sinuosus in the Upper Devonian, though of relatively small diameter (0.4–4.3 mm) than its Mesozoic and Cenozoic counterparts, extends its stratigraphical distribution and is suggestive of some primitive, small-sized decapod crustacean producers. The Osculichnus makers possibly preyed upon the Sinusichnus makers or other small invertebrates in the sediments. The overall shape and morphological details of the Late Devonian Osculichnus suggest lungfish as candidate trace makers. The fish hunting traces and associated trace fossils from South China thus provide unique insights into the palaeoecology of Late Devonian fishes.

An examination of the Devonian fishes of Michigan.

We surveyed the taxa, ecosystems, and localities of the Devonian fishes of Michigan to provide a framework for renewed study, to learn about the diversity and number of these fishes, and to investigate their connection to other North American faunas. Nineteen genera of fishes have been found in the Middle and Late Devonian deposits of Michigan, of which thirteen are ‘placoderms’ represented by material ranging from articulated head shields to ichthyoliths. As expected from the marine nature of these deposits, ‘placoderms’ are overwhelmingly arthrodire in nature, but two genera of ptyctodonts have been reported along with less common petalichthyid material. The remaining fish fauna consists of fin-spines attributed to ‘acanthodians’, two genera of potential crown chondrichthyans, an isolated dipnoan, and onychodont teeth/jaw material. There was an apparent drop in fish diversity and fossil abundance between Middle and Late Devonian sediments. This pattern may be attributed to a paucity of Late Devonian sites, along with a relative lack of recent collection efforts at existing outcrops. It may also be due to a shift towards open water pelagic environments at Late Devonian localities, as opposed to the nearshore reef fauna preserved in the more numerous Middle Devonian localities. The Middle Devonian vertebrate fauna in Michigan shows strong connections with same-age assemblages from Ohio and New York. Finally, we document the presence of partially articulated vertebrate remains associated with benthic invertebrates, an uncommon occurrence in Devonian strata outside of North America. We anticipate this new survey will guide future field work efforts in an undersampled yet highly accessible region that preserves an abundance of fishes from a critical interval in marine vertebrate evolution.

Possible courtship behaviour of Devonian fish: Evidence from large radial trace fossils in northwestern China

One kind of mysterious underwater circle observed on the seafloor near southern Amami-Oshima Island in subtropical Japan has attracted widespread attention, but its origin has long been unknown. In recent years, based on successive underwater photography, they were shown to represent the patterned structures constructed by male pufferfishes. Here we present a large radial trace fossil from the Upper Devonian Hongguleleng Formation in western Junggar, Xinjiang, northwestern China. They are circular or near-circular patterned structures consisting of numerous radial grooves and ridges. Based on morphological analysis of these specimens and comparison with the modern patterned structures made by pufferfish for courtship, we suggest that this trace fossil may be patterned structure made by male fish in the Devonian to attract females. If true, these structures would be the first reported example of courtship behaviour in the trace fossils of fish, and suggest that animal courtship behaviour has existed for at least 360 million years. These trace fossils provide new material for research on the breeding strategies and sexual selection of Devonian animals, and new insight on the origin and evolution of courtship behaviour.

Neurocranial anatomy of an enigmatic Early Devonian fish sheds light on early osteichthyan evolution.

The skull of 'Ligulalepis' from the Early Devonian of Australia (AM-F101607) has significantly expanded our knowledge of early osteichthyan anatomy, but its phylogenetic position has remained uncertain. We herein describe a second skull of 'Ligulalepis' and present micro-CT data on both specimens to reveal novel anatomical features, including cranial endocasts. Several features previously considered to link 'Ligulalepis' with actinopterygians are now considered generalized osteichthyan characters or of uncertain polarity. The presence of a lateral cranial canal is shown to be variable in its development between specimens. Other notable new features include the presence of a pineal foramen, the some detail of skull roof sutures, the shape of the nasal capsules, a placoderm-like hypophysial vein, and a chondrichthyan-like labyrinth system. New phylogenetic analyses place 'Ligulalepis' as a stem osteichthyan, specifically as the sister taxon to 'psarolepids' plus crown osteichthyans. The precise position of 'psarolepids' differs between parsimony and Bayesian analyses.

Reinterpreting the age of the uppermost ‘Old Red Sandstone' and Early Carboniferous in Scotland

ABSTRACTIn Scotland, the base of the Ballagan Formation has traditionally been placed at the first grey mudstone within a contiguous Late Devonian to Carboniferous succession. This convention places the Devonian–Carboniferous boundary within the Old Red Sandstone (ORS) Kinnesswood Formation. The consequences of this placement are that tetrapods from the Ballagan Formation were dated as late Tournaisian in age and that the ranges of typically Devonian fish found in the Kinnesswood Formation continued into the Carboniferous. The Pease Bay specimen of the fishRemigolepisis from the Kinnesswood Formation. Comparisons with its range in Greenland, calibrated against spores, show it was Famennian in age. Detailed palynological sampling at Burnmouth from the base of the Ballagan Formation proves that the early Tournaisian spore zones (VI and HD plus Cl 1) are present. TheSchopfitesspecies that occurs through most of the succession isSchopfites delicatusrather thanSchopfites claviger. The latter species defines the late Tournaisian CM spore zone. The first spore assemblage that has been found in Upper ‘ORS' strata underlying the Ballagan Formation (Preston, Whiteadder Water), containsRetispora lepidophytaand is from the early latest Famennian LL spore zone. The spore samples are interbedded with volcaniclastic debris, which shows that the Kelso Volcanic Formation is, in part, early latest Famennian in age. These findings demonstrate that the Ballagan Formation includes most of the Tournaisian with the Devonian–Carboniferous boundary positioned close to the top of the Kinnesswood Formation. The Stage 6 calcrete at Pease Bay can be correlated to the equivalent section at Carham, showing that it represents a time gap equivalent to the latest Famennian glaciation(s). Importantly, some of the recently described Ballagan Formation tetrapods are older than previously dated and now fill the key early part of Romer's Gap.

Early establishment of vertebrate trophic interactions: Food web structure in Middle to Late Devonian fish assemblages with exceptional fossilization

In past and present ecosystems, trophic interactions determine material and energy transfers among species, regulating population dynamics and community stability. Food web studies in past ecosystems are helpful to assess the persistence of ecosystem structure throughout geological times and to explore the existence of general principles of food web assembly. We determined and compared the trophic structure of two Devonian fish assemblages [(1) the Escuminac assemblage (ca. 380 Ma), Miguasha, eastern Canada and (2) the Lode assemblage (ca. 390 Ma), Straupe, Latvia] with a closer look at the Escuminac assemblage. Both localities are representative of Middle to Late Devonian aquatic vertebrate assemblages in terms of taxonomic richness (ca. 20 species), phylogenetic diversity (all major groups of lower vertebrates) and palaeoenvironment (palaeoestuaries). Fossil food web structures were assessed using different kinds of direct (i.e. digestive contents and bite marks in fossils) and indirect (e.g. ecomoiphological measurements, stratigraphic species co-occurrences) indicators. First, the relationships between predator and prey body size established for the Escuminac fishes are comparable to those of recent aquatic ecosystems, highlighting a consistency of aquatic food web structure across geological time. Second, non-metric dimensional scaling on ecomorphological variables and cluster analysis showed a common pattern of functional groups for both fish assemblages; top predators, predators, primary and secondary consumers were identified. We conclude that Devonian communities were organized in multiple trophic levels and that size-based feeding interactions were established early in vertebrate history.

A new Early Devonian (Emsian) arthrodire from the Northwest Territories, Canada, and its significance for paleogeographic reconstruction

An heterostiid arthrodire, Herasmius dayi sp. nov., is described from upper Lower Devonian marine deposits of the Bear Rock Formation along the Anderson River, Northwest Territories, Canada. New elements described for the genus for the first time include the suborbital, submarginal (also new for the family Heterostiidae), the lateral shoulder girdle with posterior lateral, anterior dorso-lateral, and posterior dorso-lateral plates and possible infragnathal plate. We present a new reconstruction of the cranial region of Herasmius, previously known only from supposedly freshwater – shallow marine deposits of roughly the same age in the Wood Bay Group of Spitsbergen. The late Early Devonian fishes that are common to the Arctic region of northwestern Canada and the island of Spitsbergen in the Svalbard archipelago of Norway, the porolepiform Heimenia and the arthrodire Herasmius described here, demonstrate the existence of a barrier-free paleogeographic connection between those continental blocks by the late Early Devonian. Comparison of the entire Anderson River vertebrate fauna with other boreal faunas of similar age indicates additional paleogeographic connections north of and around the Old Red Sandstone Continent to the Baltic region, central Europe, and even to the New Siberian Islands and South China, in contrast to most current published paleogeographical reconstructions.

Early Devonian (Late Emsian) shark fin remains (Chondrichthyes) from the Paraná Basin, southern Brazil.

We report on the pioneering discovery of Devonian fish remains in the Paraná Basin, which represents the southernmost record of fishes from that period in mainland South America. The material comes from an outcrop at the lower portion of the São Domingos Formation, within Sequence C of the Paraná-Apucarana sub-basin in Tibagi, State of Paraná. Marine invertebrates are abundant in the same strata. The dark colored fish remains were collected in situ and represent natural moulds of partially articulated shark fin rays (radials). No elements such as teeth or prismatic cartilage have been preserved with the fins rays. This can be attributed to the dissolution of calcium-phosphatic minerals at the early stages of fossilization due to diagenetic processes possibly linked to strong negative taphonomic bias. This may have contributed to the fact that fishes remained elusive in the Devonian strata of this basin, despite substantial geological work done in the Paraná State in recent decades. In addition, the scarcity of fish fossils may be explained by the fact that the Devonian rock deposits in this basin originated in a vertebrate impoverished, cold marine environment of the Malvinokaffric Realm, as previously suspected.

Ichnology of the Devonian (Emsian) Campbellton Formation, New Brunswick, Canada

The Campbellton Formation has long been known to yield a fossil assemblage of Devonian (Emsian) fish and eurypterids at its westernmost exposure near Campbellton and Atholville, and a well described flora and early land animal fauna toward its easternmost exposure near Dalhousie Junction. Although the body fossil assemblage (paleobotany, vertebrate and invertebrate paleontology), paleoecology and paleoenvironmental context of the formation have been extensively studied, ichnofossils are rare and have not been described previously. Fossils from the vertebrate and eurypterid bearing ‘Atholville Beds’ contain a low diversity ichnofossil assemblage represented by three ichnotaxa:Monomorphichnus, ?Taenidium and Helminthoidichnites. Monomorphichnus is proposed here as being produced by the produced by the activity of the eurypterid Pterygotus anglicus.

The lower actinopterygian fauna from the Lower Carboniferous Albert shale formation of New Brunswick, Canada – a review of previously described taxa and a description of a new genus and species

Abstract. The Lower Carboniferous Albert shale formation of New Brunswick, Canada, is well-known for the preservation of countless articulated lower actinopterygian palaeoniscoid fishes. This site is at the boundary between the Devonian and the Lower Carboniferous, making the lower actinopterygians preserved at this site important. The taxonomic history of previously described Albert shale formation actinopterygians is reviewed here. Many of the earliest described actinopterygian taxa from the Albert Formation are represented by poorly preserved type specimens and have the distinction of being moved from one paraphyletic genus to another paraphyletic genus. While these taxa are in need of major redescriptions, such work is premature until the large paraphyletic or polyphyletic genera they have been placed in, Palaeonicus[m], †Rhadinichthys, and †Elonichthys, are redescribed. But there is new diversity within the Albert shale formation. Here, a new lower actinopterygian species, †Lambeia pectinatus, is described from one well-preserved specimen. This new species is characterized by dorsal ridge scales with pectinated posterior margins, body scales inserted between adjacent dorsal ridge scales, body scales with pectinated posterior and ventral margins, the presence of a ventral rostro-premaxilla and a median rostral bone, a separate and distinct antorbital bone, and a single supraorbital bone. This newly described species is distinct from previously described fishes from the Albert Formation, and the morphology of this newly described species is more similar to later Carboniferous fishes rather than Devonian fishes. This suggests that morphological features commonly seen in Carboniferous fishes and rarely seen in Devonian fishes were present early in the Carboniferous.

Trackways Produced by Lungfish During Terrestrial Locomotion.

Some primarily aquatic vertebrates make brief forays onto land, creating traces as they do. A lack of studies on aquatic trackmakers raises the possibility that such traces may be ignored or misidentified in the fossil record. Several terrestrial Actinopterygian and Sarcopterygian species have previously been proposed as possible models for ancestral tetrapod locomotion, despite extant fishes being quite distinct from Devonian fishes, both morphologically and phylogenetically. Although locomotion has been well-studied in some of these taxa, trackway production has not. We recorded terrestrial locomotion of a 35 cm African lungfish (Protopterus annectens; Dipnoi: Sarcopterygii) on compliant sediment. Terrestrial movement in the lungfish is accomplished by planting the head and then pivoting the trunk. Impressions are formed where the head impacts the substrate, while the body and fins produce few traces. The head leaves a series of alternating left-right impressions, where each impact can appear as two separate semi-circular impressions created by the upper and lower jaws, bearing some similarity to fossil traces interpreted as footprints. Further studies of trackways of extant terrestrial fishes are necessary to understand the behavioural repertoire that may be represented in the fossil track record.

The phylogeny of the forearm

The natural history of the forearm started in water within the fins of some Devonian fishes. Some 385 million years later, through amazing adaptations, the forearm bones allowed the tetrapods world to colonize every other kinds of biotopes on Earth. Initially devoted to locomotion in amphibians, birds and reptiles, the forearm develops more ambitiously in the mammalian lineage. Adopting first an upright limb posture and bipedalism thereafter, the Hominidae forelimb acquires an extreme range of pro-supination and can be dedicated to other tasks, including tool making and handling. By developing unconstrained joints at the elbow and wrist level, as well as more and more specialized soft tissues like the triangular fibrocartilage complex, the human forearm reaches the most sophisticated compromise between strength, mobility and stability and becomes the hand's greatest ally.