STUDIES OF PALEOZOIC FERNS. THE MORPHOLOGY,ANATOMY, AND TAXONOMY OF ANKYROPTERIS GLABRA

Eggert , Donald A. (Yale U., New Haven, Conn.) Studies of Paleozoic ferns. The morphology, anatomy, and taxonomy of Ankyropteris glabra. Amer. Jour. Bot. 46(7): 510–520. Illus. 1959.—This is a morphological and taxonomic study of the American specimens of Ankyropteris, with the exception of A. hendricksi, that previous to this time have been referred to A. grayi, originally a Lower Carboniferous species from England, and to A. glabra, a Middle-Pennsylvanian form from Booneville, Indiana. The problem of the separation of these two closely allied species is discussed, and the original criteria for separation are questioned, on the basis of four specimens described in the present paper. The specimens are from West Mineral, Kans. and Shuler Mine in Iowa. They all have been referred to A. glabra and show extreme plasticity of several features of the plant that is correlated with the size of the stem. The major points of difference between A. glabra and A. grayi are now thought to be the presence of distantly spaced nodes in A. glabra, in contrast to closely spaced ones in A. grayi, and the presence of a small amount of mixed tissue in the stele of A. glabra, compared to a large amount in A. grayi. Well preserved axillary branches were found, whose morphology is typically that of the parent stem. It is suggested that the axillary branches were well developed in the species, and that, therefore, several orders of branching may be present in the American material. Successive orders of branching show diminution and simplification which is interpreted as an expression of the presence of determinate growth in the cauline systems of the plant, an ontogenetic pattern that is not commonly found in living forms.     

A carboniferous chondrichthyan assemblage from residues within a Triassic karst system at Cromhall quarry,Gloucestershire, England

Abstract. Sixteen different Lower Carboniferous (Tournaisian Courceyan to Chadian age, Mississippian) chondrichthyan teeth types have been extracted from Triassic erosional/aeolian fills in shallow karst systems found in the limestone quarry at Cromhall, Gloucestershire, England. These Carboniferous teeth have been found within a much larger assemblage of disarticulated bones and teeth belonging to small late Triassic terrestrial reptiles, for which Cromhall quarry is famous. The Carboniferous teeth are derived fossils, released during subaerial dissolution of the surrounding limestones. Owing to low specimen numbers and uncertainty of intraspecific character, 10 types of teeth are left in open nomenclature, although it is likely they represent new taxa. They belong to Jalodus, Ctenacanthiformes, Protacrodus, Orodus, Chomatodus, Petalodontidae, Euchondrocephali?, Helodus and Psephodus. A new genus and species, Cromhallia parvunda, of indeterminate phylogenetic relationships, is also erected. The assemblage includes also an identified suite comprising Thrinacodus ferox, Bransonella cf. nebraskensis and Stethacanthus cf. altonensis. The identification of all fish teeth found in the Cromhall assemblages as derived fossils from the Carboniferous removes any ambiguity regarding the fully terrestrial nature of the late Triassic fauna preserved in the residue‐bearing karst systems.     

Carboniferous Onychophora from Montceau‐les‐Mines,France, and onychophoran terrestrialization

The geological age of the onychophoran crown‐group, and when the group came onto land, have been sources of debate. Although stem‐group Onychophora have been identified from as early as the Cambrian, the sparse record of terrestrial taxa from before the Cretaceous is subject to contradictory interpretations. A Late Carboniferous species from the Mazon Creek biota of the USA, Helenodora inopinata, originally interpreted as a crown‐group onychophoran, has recently been allied to early Cambrian stem‐group taxa. Here we describe a fossil species from the Late Carboniferous Montceau‐les‐Mines Lagerstätte, France, informally referred to as an onychophoran for more than 30 years. The onychophoran affinities of Antennipatus montceauensis gen. nov., sp. nov. are indicated by the form of the trunk plicae and the shape and spacing of their papillae, details of antennal annuli, and the presence of putative slime papillae. The poor preservation of several key systematic characters for extant Onychophora, however, prohibits the precise placement of the Carboniferous fossil in the stem or crown of the two extant families, or the onychophoran stem‐group as a whole. Nevertheless, A. montceauensis is the most compelling candidate to date for a terrestrial Paleozoic onychophoran.     

Pecopteris (Asterotheca) saraeiP. Corsin, 1951, forme fertile de Sphenopteris damesii (Stur, 1885)

Sphenopteris damesii (Stur), a rather frequentspecies from the Sarre-Lorraine Coalfield was only known till now as a typical sphenopteridian sterile foliage. The study of a lot of specimens from recent boreholes has allowed us to show the great polymorphism of this species whose foliage, usually deeply dissected, tends to be pecopteridian in the fertile stage.The organization of fructifications and the type of included spores are described for the first time. Moreover, the comparison of the fertile specimens of Sph. damesii with those from the same horizon described by P. Corsin as Pecopteris saraei has revealed similarity in limb morphology, in the organization of fructifications, in the type of spores which proves that P. saraei is the fertile form of Sp. damesii. Consequently, P. Corsin's species is a posterior synonym of Sphenopteris damesii (Stur).The generic attribution of this species sets a nomenclatural question: the features of the fructifications agree exactly with the diagnose of the genus AsterothecaPresl but this genus till now was reserved for sporangia born by typical pecopteridian foliage. Nevertheless, the species is temporarily refered to Asterotheca until further works allow to decide about the subordination of these different characters.     

On the phylogenetic position of the palaeopteran Syntonopteroidea (Insecta: Ephemeroptera), with a new species from the Upper Carboniferous of England

A new syntonopterid, Anglolithoneura magnifica gen. et sp. n., is described from a siderite concretion (nodule) from the Late Carboniferous (Langsettian) of Lancashire County (UK). The new genus is diagnosed on hind wing venation and compared with other syntonopterid genera. The new species is the first syntonopterid formally described from the Late Carboniferous of Europe. The systematic positions of other potential Syntonopteroidea (Miracopteron mirabile, Bojophlebia prokopi, and specimens described in 1985 by J. Kukalová-Peck from Obora in the Czech Republic) are reconsidered. Wing venation synapomorphies are proposed for the Syntonopteroidea (sensu novo), and for a potential clade ((Ephemeroptera+Syntonopteroidea)+Odonatoptera) separated from the Palaeodictyopterida. The close relations of the new species with Lithoneura lameerei Carpenter, 1938 from Mazon Creek (Illinois, USA) provide additional support for a Euramerican connection during the Late Carboniferous.     

EMBRYOGENY AND REPRODUCTIVE BIOLOGY OF BOTHRODENDROSTROBUS MUNDUS (LYCOPSIDA)

Permineralized lycopsid megagametophytes and embryos from Upper Carboniferous strata (Westphalian A) at Burnley, England have been found within isolated megaspores assignable to Setosisporites. The specimens illustrate for the first time the reproductive biology and embryogeny of a free-sporing, bisporangiate, Paleozoic lycopod, and permit reinterpretation of the megagametophyte of Bothrodendrostrobus. Megagametophyte development is entirely endosporal. Embryogeny is comparable to that of the extant genus Isoetes, and is fundamentally different from that of the fossil lycopsid, Lepidocarpon—Lepidophloios. This further illustrates the diversity among Paleozoic lycopods and helps to clarify relationships among both fossil and extant lycopsid taxa.     

Carboniferous Psammichnites: Systematic Re-Evaluation,Taphonomy and Autecology

The ichnogenus Psammichnites Torell 1870 includes a wide variety of predominantly horizontal, sinuous to looped, backfilled traces, characterized by a distinctive median dorsal structure. Though commonly preserved in full relief on upper bedding surfaces, some ichnospecies of Psammichnites may be preserved in negative hyporelief. Psammichnites records the feeding activities of a subsurface animal using a siphon-like device. Several ichnogenera reflect this general behavioral pattern, including Plagiogmus Roedel 1929 and the Carboniferous ichnogenera Olivellites Fenton and Fenton 1937a and Aulichnites Fenton and Fenton 1937b. Based on analysis of specimens from the United States, Spain, and the United Kingdom, three Carboniferous ichnospecies of Psammichnites are reviewed in this paper: P. plummeri (Fenton and Fenton, 1937a), P. grumula (Romano and Meléndez 1979), and P. implexus (Rindsberg 1994). Psammichnites plummeri is the most common Carboniferous ichnospecies and is characterized by a relatively straight, continuous dorsal ridge/groove, fine transverse ridges, larger size range, and non-looping geometric pattern. It represents a grazing trace of deposit feeders. Psammichnites grumula differs from the other ichnospecies of Psammichnites by having median dorsal holes or protruding mounds. The presence of mounds or holes in P. grumula suggests a siphon that was regularly connected to the sediment-water interface. This ichnospecies is interpreted as produced by a deposit feeder using the siphon for respiration or as a device for a chemosymbiotic strategy. Psammichnites implexus is characterized by its consistently smaller size range, subtle backfill structure, and tendency to scribble. Although displaying similarities with Dictyodora scotica, P. implexus is a very shallow-tier, grazing trace. Changes in behavioral pattern, preservational style, and bedform morphology suggest a complex interplay of ecological and taphonomic controls in Carboniferous tidal-flat Psammichnites. A first distributional pattern consists of guided meandering specimens preserved in ripple troughs, probably reflecting food-searching of buried organic matter concentrated in troughs. A second is recorded by concentration of Psammichnites on ripple crests and slopes. In some cases, the course is almost straight to slightly sinuous and closely follows topographic highs, suggesting a direct control of bedform morphology on trace pattern. Occurrences of Carboniferous Psammichnites most likely represent an opportunistic strategy in marginal-marine settings. Analysis of Carboniferous Psammichnites indicates the presence of a siphon-like device in the producer and reestablishes the possibility of a molluscan tracemaker.     

Septal implosion in Late Carboniferous coiled nautiloids from Ohio

Mapes, R.H. & McComas, G.A. 2010: Septal implosion in Late Carboniferous coiled nautiloids from Ohio. Lethaia, 10.1111/j.1502–3931.2009.00213.x More than 200 relatively mature coiled nautiloid specimens, assigned to Metacoceras mcchesneyi, were recovered from an Upper Carboniferous shale in northeastern Ohio. Twenty‐seven undistorted specimens reveal that the septa in every specimen were collapsed and/or telescoped. This septal collapse without external shell distortion could only have been accomplished by limited implosion due to excessive pressure. Analysis of the fossils, sediment and the depositional environment indicate that after burial, the nautiloid cameral spaces were probably filled with both liquid and gas, and the body chamber was filled with semi‐solid thixotropic mud. To prevent conch collapse at the time of septal implosion, the thixotropic mud filling the nautiloid body chamber acted as a liquid at the time of stress release during septal failure. The stress was produced by combined lithostatic and hydrostatic pressures, which fluidized the unlithified thixotropic mud that flowed from the body chamber into the phragmocone during septal collapse. After the septal implosion and when flowage ceased, the thixotropic mud quickly resolidified into a solid state providing internal conch support that prevented the collapse of the conch. □Carboniferous, nautiloids, septal implosion, taphonomy, thixotropic mud.     

The role of comparative morphology and anatomy in interpreting the systematics of fossil gymnosperms

This paper is an analysis of the systematics and phylogeny of gymnosperms as recently proposed by Meyen (Bot. Rev.50(1): 1–111. 1984). Attention is focused on the philosophical approach and on the fundamental concepts that frame the systematic scheme. Morphological interpretations are examined in relation to the concept of homology, and criteria employed for the recognition of whole plants from fossil evidence are evaluated. An examination of fossils from Upper Devonian and Lower Carboniferous strata reveals that only the ovules and ovulate fructifications constitute unequivocal evidence for gymnosperms in these strata. Such examination also reveals that they all can be interpreted as conforming to the same basic structure. If true, there is no evidence for more than one major group of gymnosperms in Devonian and Lower Carboniferous strata. Although many conclusions of Meyen are not accepted, his work plays a valuable role in focusing attention on important, unresolved questions of gymnosperm systematics, and provides a poignant stimulus for the proposal of alternative hypotheses.     

COPROMYXELLA: A NEW GENUS OF ACRASIDAE

A new genus of cellular slime molds, Copromyxella, is described together with four species that comprise it. Since it resembles Zopf's Copromyxa more than any genus presently recognized, but differs from it in important characteristics such as the smaller dimensions of its cellular elements and the delicacy of its fructifications, the name Copromyxella is chosen for the new taxon. Four species are included: C. silvatica, C. filamentosa, C. spicata, and C. coralloides. All are characterized by small myxamoebae with lobose and potentially “explosive” pseudopodia and may assume limax forms in liquid media; all possess nuclei with centrally positioned nucleoli; all lack true contractile vacuoles (with a single possible exception); all aggregate without stream formation; and all form fructifications with no demarcation into stalks and sori. Taxonomically the genus belongs in the Acrasidae with Copromyxa, Guttulinopsis and Acrasis rosea rather than in the better known Dictyostelidae that includes Dictyostelium and Polysphondylium.     

The status of Jambadostrobus Chandra and Surange (Glossopteridales)

Jambadostrobus was established to accommodate fossils consisting of several multiovulate elliptical–ovate fructifications attached to the midline of glossopterid leaves. Two species have been assigned to the genus: J. pretiosus (the type species) and J. hillii from the Late Permian of India and Early Permian of Australia, respectively. Re-investigation of the original specimens reveals that only solitary fructifications are attached to the subtending leaf in J. pretiosus, hence the species is transferred to Plumsteadia, which was founded on equivalent characters. The putative reproductive organs constituting the single Australian specimen of J. hillii are re-interpreted to constitute a broad area of preservational damage on the leaf, hence Jambadostrobus is considered to be a nomen illegitimum.     

The first described Arsinoitherium from the upper Eocene Aydim Formation of Oman: Biogeographic implications

A new fossiliferous locality is discovered from the upper Eocene Aydim Formation, in Dhofar, Southern Sultanate of Oman. A left ulna of Arsinoitherium is described, and cranial and postcranial specimens found in close proximity are referred to the same taxon. The locality is promising for the recovery of additional fossil specimens. Moreover, the presence of Arsinoitherium in Oman is of biogeographic significance; as the Red Sea did not exist during the late Eocene, these large-bodied animals were able to freely travel between what is now the Arabian Peninsula and continental Africa.     

Filicales y Bennettitales del Cretácico Inferior de Carazuelo, provincia de Soria, España

Silicified woods of the fern Tempskya riojana Barale and Viera and the Bennettitales Cycadeoidea barbarae Crisafulli nov. sp., found together with undetermined conifer woods, from the NW of Carazuelo, province Soria, are described. This site is located south of the so-called San Saturio fault which runs parallel to Road N-234. The fossil trunks are included in the “Conglomerados poligénicos, areniscas y arcillas” fluviatile sediments, dated as Paleogene. The original source of these fossils could be Tera and/or Oncala Groups, both Early Cretaceous in age and outcropping close by at Fuentetecha, Fuensaúco and North of Soria. Similar plant fossil findings from this region are reported and some mistakes in the geological mapping are analyzed. The Tempskya specimens were histologically poorly preserved, but had enough anatomical characters to be undoubtedly assigned to Tempskya riojana. The new species Cycadeoidea barbarae is described, with fairly well preserved cellular structure, viz., pith, vascular cylinder, cortex, foliar/branch traces, as well as strobili surrounded by foliar scales and apical seminal cones. An important and new aspect of the new species is that it includes morphologically and anatomically preserved both fructifications and vegetative parts, whereas these are usually find separated by other species of Bennettitales.     

THE MORPHOLOGY AND RELATIONSHIPS OF RHODEA,TELANGIUM, TELANGIOPSIS,AND HETERANGIUM

This study deals with four form or organ genera from the Upper Mississippian (Chester Series) of the Illinois Basin, and provides evidence that they were produced by a single natural genus with gymnospermous affinity. The plant remains—compressions, impressions, petrifactions, and specimens that combine compression or impression with petrifaction—allow examination of both external morphology and internal anatomy. The specimens include foliage corresponding to Rhodea, stems and petioles corresponding to Heterangium, and synangiate fructifications corresponding to either Telangium or Telangiopsis. The stems and foliage are considered parts of the same plant because of the identity of the anatomical and cuticular features of petioles attached to stem and those petioles with attached foliage. The fertile material is regarded as part of the same plant because: (1) The anatomy of axes of the fertile specimens is like that of the sterile specimens. (2) A single specimen may contain both sterile Rhodea-type axes and fertile regions. (3) Axes bearing synangia have the same size and patterns of divisions as the sterile foliage. Features that indicate lyginopterid affinities include: (1) Equal forking of the petiole. (2) Presence of fiber bands in the outer cortex and sclerotic nests in the inner part of the cortex. (3) Crowded circular bordered pits on the lateral walls of the metaxylem tracheids. (4) The presence of a small amount of secondary xylem. A variety of structural details of the stem and petiole suggest the genus Heterangium. The phyletic position of the plant that produced Rhodea, Telangium, Telangiopsis, and Heterangium is reviewed in light of such discoveries as the presence of a planated frond that lacks a lamina and the presence of both monolete and trilete microspores in a single synangium.     

ACHLAMYDOCARPON VARIUS COMB. NOV.: MORPHOLOGY AND REPRODUCTIVE BIOLOGY

Structurally preserved arborescent lycopsid fructifications are described from Pennsylvanian age strata in eastern Kentucky and southern Illinois. Achlamydocarpon varius comb. nov. is the name proposed for these cones and previously reported isolated megasporophylls described as Lepidostrobophyllum varius. The specimens range up to 3.5 cm long and represent cone apices. Megasporophylls are spirally arranged and attached to the cone axis at an acute angle. Megasporangia are large with a wall two cell layers thick. Each sporangium contains one large, presumably functional megaspore, and three smaller, abortive megaspores. Functional and abortive spores possess a prominent apical tuft (massa) that covers up to one-third of the proximal surface of the spore. Sporoderm ultrastructure is detailed together with a comparison of morphologically similar sporae dispersae megaspores. The possible function of the megaspore massa is discussed as it relates to the reproductive biology of the cone.     

The Fish Swimming Trace Undichna from the Mississippian Mauch Chunk Formation,Eastern Pennsylvania

Undichna, the swimming trace of fish, was recovered from the middle member of the Mauch Chunk Formation in eastern Pennsylvania in strata of Late Mississippian (Visean) age. These traces represent the only evidence of fish known from the Mauch Chunk Formation and the Carboniferous of Eastern Pennsylvania. The Mauch Chunk Formation in the study area is characterized by an ephemeral fluvial depositional environment that yields a diverse invertebrate ichnoassemblage of the Scoyenia ichnofacies and a tetrapod footprint assemblage dominated by the tracks of temnospondyl amphibians. The Undichna specimens are preserved on fine-grained, mudstone-draped, rippled sandstone. Two specimens, assigned to U. Britannica, consist of pairs of well-defined, narrowly incised, sinusoidal wave traces that are out-of-phase. Two specimens, assigned to U. quina, consist of two pairs of in-phase sinusoidal waves intersected by an additional single wave with a greater amplitude. Two specimens, each composed of a single wave, are assigned to U. unisulca.

The slabs of rock with the Undichna traces also preserve tetrapod undertracks assigned to Batrachichnus, Matthewichnus, and Hylopus. This trace fossil association indicates the presence of small fish, some with caudal and/or anal fins and some with pectoral, pelvic, and anal and/or caudal fins, that touched the sediment during periods of intermittent flooding of subaerial surfaces walked upon by early tetrapods. Examples of Undichna from Mississippian or older deposits, especially from a fluvial paleoenvironment, are rare; few have been reported from the Devonian and the Lower Carboniferous.     

Fossil juvenile coelacanths from the Devonian of South Africa shed light on the order of character acquisition in actinistians

A new coelacanth genus from the Famennian (Upper Devonian) of South Africa is described, principally from presumed juveniles. S erenichthys kowiensis gen. et sp. nov. uniquely shares with Diplocercides a ventral expansion of the elbow‐like lachrymojugal, as well as a symmetrical diphycercal tail supported by expanded neural and haemal spines and radials. Serenichthys is distinguished from Diplocercides by a number of derived characters, including possession of longer anterior parietals, a more crescent‐shaped postorbital with a more anteriorly positioned infraorbital canal, and a far smaller squamosal, which is well separated from the skull roof. By contrast, Serenichthys appears to lacks a second dorsal fin lobe, a derived feature present in Diplocercides. Most specimens of Serenichthys are between 3 and 6 cm in length. They have large eyes, and dermal bones of the skull ornamented with long wavy ridges, similar to the dermal ornament of other Devonian coelacanths such as Gavinia. Larger isolated operculae also collected from the Waterloo Farm locality and attributed to Serenichthys indicate that with growth the ridges on the dermal bones transformed into elongate tubercles, reminiscent of those of Diplocercides and Carboniferous taxa. Phylogenetic analysis resolves Serenichthys as the sister group of Holopterygius and all known post‐Devonian coelacanths. The clade including the unusual leaf‐shaped coelacanths, the Devonian Holopterygius and Carboniferous Allenypterus, branches from the coelacanth lineage immediately crownward of Serenichthys. The presence of abundant juveniles within an estuarine setting strongly parallels the discovery of similarly sized juveniles of Rhabdoderma exiguus together with eggs and yolk‐sack larvae in the Upper Carboniferous Mazon Creek biota. It is therefore argued that Serenichthys, like Rhabdoderma, was using the sheltered estuarine environment as a nursery. © 2015 The Linnean Society of London     

The identity of the Ordovician (Darriwilian) graptolite Fucoides dentatus Brongniart, 1828

Abstract: The biostratigraphically important Middle Ordovician (Darriwilian) biserial graptolite Fucoides dentatus Brongniart, 1828 is redescribed and illustrated from its type material and from additional specimens collected at the type locality – Lévis, Quebec, Canada. It is referred to Levisograptus gen. nov., which includes also the austrodentatus group of early axonophoran graptolites. The species has previously been confused with a younger, mid‐Darriwilian species, now referred to as Eoglyptograptus gerhardi sp. nov., and recognized as the type species of the genus Eoglyptograptus Mitchell. Both species can be differentiated easily by their respective proximal development types and show nonoverlapping biostratigraphical ranges. Levisograptus dentatus (Brongniart) is an important biostratigraphical index species in the early Darriwilian. Eoglyptograptus species are found in the higher Darriwilian and are biogeographically restricted to the Atlantic Faunal Realm.