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A New Osteolepidid Fish From
Rea. West. Aust. MU8. 1985, 12(3): 361-377 ANew Osteolepidid Fish from the Upper Devonian Gogo Formation, Western Australia J.A. Long* Abstract A new osteolepidid crossopterygian, Gogonasus andrewsi gen. et sp. nov., is des cribed from a single fronto-ethmoidal shield and associated ethmosphenoid, from the Late Devonian (Frasnian) Gogo Formation, Western Australia. Gogonasus is is distinguished from other osteolepids by the shape and proportions of the fronto ethmoidal shield, absence of palatal fenestrae, well developed basipterygoid pro cesses and moderately broad parasphenoid. The family Osteolepididae is found to be paraphyletic, with Gogonasus being regarded as a plesiomorphic osteolepidid at a similar level of organisation to Thursius. Introduction Much has been published on the well-preserved Late Devonian fish fauna from the Gogo Formation, Western Australia, although to date all the papers describing fish have been on placoderms (Miles 1971; Miles and Dennis 1979; Dennis and Miles 1979-1983; Young 1984), palaeoniscoids (Gardiner 1973, 1984; Gardiner and Bartram 1977) or dipnoans (Miles 1977; Campbell and Barwick 1982a, 1982b, 1983, 1984a). This paper describes the only osteolepiform from the fauna (Gardiner and Miles 1975), a small snout with associated braincase, ANU 21885, housed in the Geology Department, Australian National University. The specimen, collected by the Australian National University on the 1967 Gogo Expedition, was prepared by Dr S.M. Andrews (Royal Scottish Museum) and later returned to the ANU. Onychodus is the only other crossopterygian in the fauna. In its proportions and palatal structure the new specimen provides some additional new points of the anatomy of osteolepiforms. Few Devonian crossopte rygians are known from Australia, and so the specimen is significant in having resemblances to typical Northern Hemisphere species. -
'Placoderm' (Arthrodira)
Jobbins et al. Swiss J Palaeontol (2021) 140:2 https://doi.org/10.1186/s13358-020-00212-w Swiss Journal of Palaeontology RESEARCH ARTICLE Open Access A large Middle Devonian eubrachythoracid ‘placoderm’ (Arthrodira) jaw from northern Gondwana Melina Jobbins1* , Martin Rücklin2, Thodoris Argyriou3 and Christian Klug1 Abstract For the understanding of the evolution of jawed vertebrates and jaws and teeth, ‘placoderms’ are crucial as they exhibit an impressive morphological disparity associated with the early stages of this process. The Devonian of Morocco is famous for its rich occurrences of arthrodire ‘placoderms’. While Late Devonian strata are rich in arthrodire remains, they are less common in older strata. Here, we describe a large tooth-bearing jaw element of Leptodontich- thys ziregensis gen. et sp. nov., an eubrachythoracid arthrodire from the Middle Devonian of Morocco. This species is based on a large posterior superognathal with a strong dentition. The jawbone displays features considered syna- pomorphies of Late Devonian eubrachythoracid arthrodires, with one posterior and one lateral row of conical teeth oriented postero-lingually. μCT-images reveal internal structures including pulp cavities and dentinous tissues. The posterior orientation of the teeth and the traces of a putative occlusal contact on the lingual side of the bone imply that these teeth were hardly used for feeding. Similar to Compagopiscis and Plourdosteus, functional teeth were pos- sibly present during an earlier developmental stage and have been worn entirely. The morphological features of the jaw element suggest a close relationship with plourdosteids. Its size implies that the animal was rather large. Keywords: Arthrodira, Dentition, Food web, Givetian, Maïder basin, Palaeoecology Introduction important to reconstruct character evolution in early ‘Placoderms’ are considered as a paraphyletic grade vertebrates. -
Coincidence of Photic Zone Euxinia and Impoverishment of Arthropods
www.nature.com/scientificreports OPEN Coincidence of photic zone euxinia and impoverishment of arthropods in the aftermath of the Frasnian- Famennian biotic crisis Krzysztof Broda1*, Leszek Marynowski2, Michał Rakociński1 & Michał Zatoń1 The lowermost Famennian deposits of the Kowala quarry (Holy Cross Mountains, Poland) are becoming famous for their rich fossil content such as their abundant phosphatized arthropod remains (mostly thylacocephalans). Here, for the frst time, palaeontological and geochemical data were integrated to document abundance and diversity patterns in the context of palaeoenvironmental changes. During deposition, the generally oxic to suboxic conditions were interrupted at least twice by the onset of photic zone euxinia (PZE). Previously, PZE was considered as essential in preserving phosphatised fossils from, e.g., the famous Gogo Formation, Australia. Here, we show, however, that during PZE, the abundance of arthropods drastically dropped. The phosphorous content during PZE was also very low in comparison to that from oxic-suboxic intervals where arthropods are the most abundant. As phosphorous is essential for phosphatisation but also tends to fux of the sediment during bottom water anoxia, we propose that the PZE in such a case does not promote the fossilisation of the arthropods but instead leads to their impoverishment and non-preservation. Thus, the PZE conditions with anoxic bottom waters cannot be presumed as universal for exceptional fossil preservation by phosphatisation, and caution must be paid when interpreting the fossil abundance on the background of redox conditions. 1 Euxinic conditions in aquatic environments are defned as the presence of H2S and absence of oxygen . If such conditions occur at the chemocline in the water column, where light is available, they are defned as photic zone euxinia (PZE). -
Copyrighted Material
06_250317 part1-3.qxd 12/13/05 7:32 PM Page 15 Phylum Chordata Chordates are placed in the superphylum Deuterostomia. The possible rela- tionships of the chordates and deuterostomes to other metazoans are dis- cussed in Halanych (2004). He restricts the taxon of deuterostomes to the chordates and their proposed immediate sister group, a taxon comprising the hemichordates, echinoderms, and the wormlike Xenoturbella. The phylum Chordata has been used by most recent workers to encompass members of the subphyla Urochordata (tunicates or sea-squirts), Cephalochordata (lancelets), and Craniata (fishes, amphibians, reptiles, birds, and mammals). The Cephalochordata and Craniata form a mono- phyletic group (e.g., Cameron et al., 2000; Halanych, 2004). Much disagree- ment exists concerning the interrelationships and classification of the Chordata, and the inclusion of the urochordates as sister to the cephalochor- dates and craniates is not as broadly held as the sister-group relationship of cephalochordates and craniates (Halanych, 2004). Many excitingCOPYRIGHTED fossil finds in recent years MATERIAL reveal what the first fishes may have looked like, and these finds push the fossil record of fishes back into the early Cambrian, far further back than previously known. There is still much difference of opinion on the phylogenetic position of these new Cambrian species, and many new discoveries and changes in early fish systematics may be expected over the next decade. As noted by Halanych (2004), D.-G. (D.) Shu and collaborators have discovered fossil ascidians (e.g., Cheungkongella), cephalochordate-like yunnanozoans (Haikouella and Yunnanozoon), and jaw- less craniates (Myllokunmingia, and its junior synonym Haikouichthys) over the 15 06_250317 part1-3.qxd 12/13/05 7:32 PM Page 16 16 Fishes of the World last few years that push the origins of these three major taxa at least into the Lower Cambrian (approximately 530–540 million years ago). -
Redescription of Yinostius Major (Arthrodira: Heterostiidae) from the Lower Devonian of China, and the Interrelationships of Brachythoraci
bs_bs_banner Zoological Journal of the Linnean Society, 2015. With 10 figures Redescription of Yinostius major (Arthrodira: Heterostiidae) from the Lower Devonian of China, and the interrelationships of Brachythoraci YOU-AN ZHU1,2, MIN ZHU1* and JUN-QING WANG1 1Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China 2University of Chinese Academy of Sciences, Beijing 100049, China Received 29 December 2014; revised 21 August 2015; accepted for publication 23 August 2015 Yinosteus major is a heterostiid arthrodire (Placodermi) from the Lower Devonian Jiucheng Formation of Yunnan Province, south-western China. A detailed redescription of this taxon reveals the morphology of neurocranium and visceral side of skull roof. Yinosteus major shows typical heterostiid characters such as anterodorsally positioned small orbits and rod-like anterior lateral plates. Its neurocranium resembles those of advanced eubrachythoracids rather than basal brachythoracids, and provides new morphological aspects in heterostiids. Phylogenetic analysis based on parsimony was conducted using a revised and expanded data matrix. The analysis yields a novel sce- nario on the brachythoracid interrelationships, which assigns Heterostiidae (including Heterostius ingens and Yinosteus major) as the sister group of Dunkleosteus amblyodoratus. The resulting phylogenetic scenario suggests that eubrachythoracids underwent a rapid diversification during the Emsian, representing the placoderm response to the Devonian Nekton Revolution. The instability of the relationships between major eubrachythoracid clades might have a connection to their longer ghost lineages than previous scenarios have implied. © 2015 The Linnean Society of London, Zoological Journal of the Linnean Society, 2015 doi: 10.1111/zoj.12356 ADDITIONAL KEYWORDS: Brachythoraci – Heterostiidae – morphology – phylogeny – Placodermi. -
A Large Late Devonian Arthrodire (Vertebrata, Placodermi) from Poland
Estonian Journal of Earth Sciences, 2018, 67, 1, 33–42 https://doi.org/10.3176/earth.2018.02 A large Late Devonian arthrodire (Vertebrata, Placodermi) from Poland Piotr Szreka and Olga Wilkb a Polish Geological Institute–National Research Institute, 4 Rakowiecka Street, 00-975 Warszawa, Poland; [email protected] b Faculty of Geology, University of Warsaw, 93 Żwirki i Wigury Street, 02-089 Warszawa, Poland; [email protected] Received 1 August 2017, accepted 31 October 2017, available online 19 January 2018 Abstract. The arthrodire placoderm, Dunkleosteus sp., is reported from the Upper Devonian (Frasnian) of the Holy Cross Mountains, Poland. The material comprises partially preserved remains of two individuals found in the Kellwasser-like horizon of the Płucki locality. The remains are preserved as broken bone fragments redeposited from shallower environment into deep-shelf conditions. They are labelled as Dunkleosteus sp. and seem similar to Dunkleosteus marsaisi from the Famennian of Morocco. It is likely that the form from Poland represents a new species that requires further collecting and study of new specimens. The described specimens are the oldest occurrence of the genus Dunkleosteus in Europe, the most complete one from Poland and one of the biggest placoderms with a head about 60 cm long. Key words: Dunkleosteus, Upper Devonian, Frasnian, Holy Cross Mountains, Poland. INTRODUCTION D. marsaisi Lehman, 1954 from the early Famennian of Morocco (Lehman 1956). The genus Dunkleosteus (formerly Dinichthys in part) Although tens of placoderm fossil remains were includes about eight species (if including D. belgicus collected in Płucki during long-term excavation works (Leriche), 1931) which are found in Laurussia (USA, between 1996 and 2006 (see Szrek 2008, 2009; Szrek & Canada, Belgium, Poland) and Gondwana (Morocco). -
Devonian Daniel Childress Parkland College
Parkland College A with Honors Projects Honors Program 2019 Did You Know: Devonian Daniel Childress Parkland College Recommended Citation Childress, Daniel, "Did You Know: Devonian" (2019). A with Honors Projects. 252. https://spark.parkland.edu/ah/252 Open access to this Poster is brought to you by Parkland College's institutional repository, SPARK: Scholarship at Parkland. For more information, please contact [email protected]. GENUS PHYLUM CLASS ORDER SIZE ENVIROMENT DIET: DIET: DIET: OTHER D&D 5E “PERSONAL NOTES” # CARNIVORE HERBIVORE SIZE ACANTHOSTEGA Chordata Amphibia Ichthyostegalia 58‐62 cm Marine (Neritic) Y ‐ ‐ small 24in amphibian 1 ACICULOPODA Arthropoda Malacostraca Decopoda 6‐8 cm Marine (Neritic) Y ‐ ‐ tiny Giant Prawn 2 ADELOPHTHALMUS Arthropoda Arachnida Eurypterida 4‐32 cm Marine (Neritic) Y ‐ ‐ small “Swimmer” Scorpion 3 AKMONISTION Chordata Chondrichthyes Symmoriida 47‐50 cm Marine (Neritic) Y ‐ ‐ small ratfish 4 ALKENOPTERUS Arthropoda Arachnida Eurypterida 2‐4 cm Marine (Transitional) Y ‐ ‐ small Sea scorpion 5 ANGUSTIDONTUS Arthropoda Malacostraca Angustidontida 6‐9 cm Marine (Pelagic) Y ‐ ‐ small Primitive shrimp 6 ASTEROLEPIS Chordata Placodermi Antiarchi 32‐35 cm Marine (Transitional) Y ‐ Y small Placo bottom feeder 7 ATTERCOPUS Arthropoda Arachnida Uraraneida 1‐2 cm Marine (Transitional) Y ‐ ‐ tiny Proto‐Spider 8 AUSTROPTYCTODUS Chordata Placodermi Ptyctodontida 10‐12 cm Marine (Neritic) Y ‐ ‐ tiny Half‐Plate 9 BOTHRIOLEPIS Chordata Placodermi Antiarchia 28‐32 cm Marine (Neritic) ‐ ‐ Y tiny Jawed Placoderm 10 -
Facies Differentiation and Late Devonian Placoderms Fossils in the Holy Cross Mountains
Przegl¹d Geologiczny, vol. 54, nr 6, 2006 Zró¿nicowanie facjalne a skamienia³oœci póŸnodewoñskich plakodermów w Górach Œwiêtokrzyskich Piotr Szrek* Facies differentiation and Late Devonian placoderms fossils in the Holy Cross Mountains. Prz. Geol., 54: 521–524. S u m m a r y. Main Late Devonian placoderm taxa known from the Holy Cross Mountains are characterised. The distribution of the Late Devonian placoderm fossils is described. Variation in their occurrences depend on the sedimentation environment of the rocks which contain fossils of this group. Connections between the Holy Cross Mountains placoderms development and the synsedimentary tectonic processes active in this area during the Late Devonian is discussed, and the local faunas compared to classic assemblages of the same age from Latvia. Key words: Placodermi, synsedimentation tectonic, Late Devonian, facies, Holy Cross Mountains Placodermi (ryby pancerne) to gromada krêgowców Plakodermy œwiêtokrzyskie wodnych, która pojawi³a siê w sylurze, a wymar³a z koñcem dewonu. Ich maksymalny stopieñ zró¿nicowania Znalezione i opisane dotychczas póŸnodewoñskie pla- przypada na póŸny dewon — wtedy to plakodermy zdomi- kodermy z Gór Œwiêtokrzyskich mo¿na podzieliæ na dwie nowa³y niemal wszystkie morskie nisze ekologiczne, zasadnicze grupy. Kryterium zastosowanego podzia³u jest wytwarzaj¹c ró¿norodne typy specjalizacyjne, umo¿li- sposób zdobywania po¿ywienia oraz stopieñ przywi¹zania wiaj¹ce ¿ycie zarówno w otwartym basenie morskim, œro- do okreœlonych œrodowisk, a tak¿e stopieñ opancerzenia dowisku przyrafowym, jak te¿ w œrodowiskach cia³a. brakicznych. W Górach Œwiêtokrzyskich grupa ta jest Do pierwszej grupy mo¿na zaliczyæ wszystkie pla- bogato reprezentowana w materiale kopalnym i by³a oma- kodermy, bêd¹ce aktywnymi myœliwymi, u których pancerz wiana w licznych pracach od ponad stu lat (m.in. -
Comments on the Late Devonian Placoderms from the Holy Cross Mountains (Poland)
Comments on the Late Devonian placoderms from the Holy Cross Mountains (Poland) ALEXANDER IVANOV andMICHAŁ GINTER Ivanov, A. & Ginter,M. 1997. Comments on the Late Devonian placoderms from the Holy Cross Mountains (Poland).- Acta Palaeontologica Polonica 4,3,4I34f6. Taxonomy of the Late Devonian placoderm remains from the Holy Cross Mountains, Poland, described by Gorizdro-Kulczycka (L934,1950) and Kulczycki (1956, 1957),is revised. Several recently found specimens are also mentioned. The old collections are composed of representatives of Ptyctodontidae, Holonematidae, Plourdosteidae, Pholi- dosteidae, Selenosteidae, Titanichthyidae and Dinichthyidae, the latter with an unde- scribed species of Eastmanosteus. Newly found specimens belong to Ptyctodontidae, Plourdosteidae and Dinichthyidae. The occurrence of the Antiarcha in the Late Devonian of the Holy Cross Mountains, suggestedby former authors, has not been confirmed. K e y w o rd s : Placodermi,Late Devonian, Holy Cross Mountains, Poland. Alexander Ivanov [[email protected]], Laboratory of Paleontology, Institute of the Earth Crust, Sankt-Petersburg University, 16 Liniya 29, 199178 St.Petersburg, Russia. Michał Ginter [email protected]], InsĘtut Geologii Podstawowej, Uniwersytet War szaw ski, ul. Zw irki i Wi gury 9 3, 02 -089 War szaw a, P oland. Introduction The main goals of this study are to revise placodermsfrom the Late Devonian of the Holy Cross Mountains collected by Jan Czarnocki, Julian Kulczycki and Zinuda Gorizdro-Kulczycka in the first half of the century (the material now housed in the Museum of the Polish Geological Instituteand in the Museum of the Earth in Warsaw), and to describe a fęw new specimenscollected recently by Jerzy Dzik and Grzegorz Racki. -
Fossils Provide Better Estimates of Ancestral Body Size Than Do Extant
Acta Zoologica (Stockholm) 90 (Suppl. 1): 357–384 (January 2009) doi: 10.1111/j.1463-6395.2008.00364.x FossilsBlackwell Publishing Ltd provide better estimates of ancestral body size than do extant taxa in fishes James S. Albert,1 Derek M. Johnson1 and Jason H. Knouft2 Abstract 1Department of Biology, University of Albert, J.S., Johnson, D.M. and Knouft, J.H. 2009. Fossils provide better Louisiana at Lafayette, Lafayette, LA estimates of ancestral body size than do extant taxa in fishes. — Acta Zoologica 2 70504-2451, USA; Department of (Stockholm) 90 (Suppl. 1): 357–384 Biology, Saint Louis University, St. Louis, MO, USA The use of fossils in studies of character evolution is an active area of research. Characters from fossils have been viewed as less informative or more subjective Keywords: than comparable information from extant taxa. However, fossils are often the continuous trait evolution, character state only known representatives of many higher taxa, including some of the earliest optimization, morphological diversification, forms, and have been important in determining character polarity and filling vertebrate taphonomy morphological gaps. Here we evaluate the influence of fossils on the interpretation of character evolution by comparing estimates of ancestral body Accepted for publication: 22 July 2008 size in fishes (non-tetrapod craniates) from two large and previously unpublished datasets; a palaeontological dataset representing all principal clades from throughout the Phanerozoic, and a macroecological dataset for all 515 families of living (Recent) fishes. Ancestral size was estimated from phylogenetically based (i.e. parsimony) optimization methods. Ancestral size estimates obtained from analysis of extant fish families are five to eight times larger than estimates using fossil members of the same higher taxa. -
Ptyctodontid Fishes (Vertebrata, Placodermi) from the Late Devonian Gogo Formation, Western Australia, with a Revision of the European Genus Ctenurella 0Rvig, 1960
Ptyctodontid fishes (Vertebrata, Placodermi) from the Late Devonian Gogo Formation, Western Australia, with a revision of the European genus Ctenurella 0rvig, 1960 John A. LONG Department of Earth and Planetary Sciences, The Western Australian Museum, Francis Street, Perth, Western Australia, 6000 (Australia) Long J. A. 1997. — Ptyctodontid fishes (Vertebrata, Placodermi) from the Late Devonian Gogo Formation, Western Australia, with a revision of the European genus Ctenurella 0rvlg, 1960. Geodiversitas 19 (3) : 515-555. ABSTRACT A new, almost complete specimen of the ptyctodontid placoderm Campbellodus decipiens Miles et Young, 1977 enables description of the skull toof, trunk shield, visceral skeleton, pelvic girdle, dermal scale cover, and parts of the vertebtal column. A new reconstruction of the head shield of Ctenurella gladbachensis 0rvig, 1960 from Bergisch-Gladbach permits this taxon to be genetically defined from the Gogo species pteviously referred to that genus. The Gogo form is here referred to Austroptyctodus n.g. A new spe KEYWORDS cimen of Austroptyctodus gardineri Miles et Young, 1977, together with new Ptyctodontida, observations of Chelyophorus verneuili Agassiz, 1844 and Ctenurella gladba Devonian, chensis 0rvig, 1960, shows new information fot the endocranium, the hyoid Placodermi, Gogo, arch and visceral skeleton, identifying the previously identified "metaptery- Australia, goid" elements as paired nasal bones. The large visceral skeleton bone poste Austroptyctodus n.g., rior to the jaw joint in ptyctodontids is here identified as an elongated Ctenurella, Chelyophorus. interhyal. RESUME Une nouvelle description du toit crânien, de la cuirasse thoracique, du sque lette viscéral, de la ceinture pelvienne, de l'écaillure et de quelques éléments de la colonne vertébtale est proposée à partit d'un nouveau spécimen sub complet du ptyctodonte Campbellodus decipiens Miles et Young, 1977. -
Fossil Fishes (Arthrodira and Acanthodida) from the Upper Devonian Chadakoin Formation of Erie County, Pennsylvania1
Fossil Fishes (Arthrodira and Acanthodida) from the Upper Devonian Chadakoin Formation of Erie County, Pennsylvania1 KEVIN M. YEAGER2, Department of Geosciences, Edinboro University of Pennsylvania, Edinboro, PA 16444 ABSTRACT. Several fossil fish were discovered in 1994 in the Upper Devonian Chadakoin Formation, near Howard Falls, just outside of Edinboro, Erie County, Pennsylvania. These fossils are fragmentary in nature and have been described based on their morphology. They are identified as the median dorsal plate of the large arthrodire Dunkleosteus terrelli Newberry, 1873, and the spines of probable acanthodian fishes. The identification of the median dorsal plate of Dunkleosteus represents a new occurrence of the genus. In general, these discoveries are of scientific interest because very little is known about the composition of the fish fauna that inhabited the Devonian shallow seas of northwestern Pennsylvania. OHIO J. SCI. 96 (3): 52-56,1996 INTRODUCTION Pennsylvania were deposited in a shallow water en- This study was an outgrowth of geologic field map- vironment. The shallower bottom sediments were oxy- ping being conducted in the Howard Falls area near genated by waves and currents, and supported a variety Edinboro, Pennsylvania. In August 1994, the first of of scavengers. several vertebrate fossil specimens were discovered. The Nonetheless, reduced preservation potential alone first specimen was excavated, reconstructed, and identi- does not explain why fossil fishes are poorly known fied by specialists from the Pennsylvania State Museum, from Pennsylvania. The Devonian rocks of southern Harrisburg. Since that time, four more vertebrate speci- New York were deposited in shallow waters also, but mens have been collected. These specimens were have yielded a diverse fish fauna (Eastman 1907).