Fig 4 - uploaded by David K. Brezinski
Content may be subject to copyright.
Ditomopygine trilobite Simulopaladin tridentifer sp. nov. from Kungurian–Roadian (Permian) of Wadi Khawr al Jaramah, Oman. A. Holotype, enrolled complete specimen, NHMUKPI It 29096; cephalon in dorsal view (A 1 ); pygidium and half thorax in dorsal (A 2 ), lateral (A 3 ), and anterior (A 4 ) views. B. NHMUKPI It 29097; cranidium in dorsal (B 1 ), anterior (B 2 ), and lateral (B 3 ) views. C. NHMUKPI It 29100; incomplete cephalon in dorsal (C 1 ), anterior (C 2 ), and lateral (C 3 ) views. D. Enrolled specimen, NHMUKPI It 29101; cephalon in dorsal (D 1 ) and lateral (D 2 ) views; pygidium and half thorax in dorsal view (D 3 ). E. NHMUKPI It 29099; cranidium and 4 thoracic segments in dorsal view. F. NHMUKPI It 29095; cephalon with cuticle showing occipital tubercles in dorsal (F 1 ) and lateral (F 2 ) views. Scale bars 2.5 mm.
Source publication
Late Mississippian and earliest Pennsylvanian trilobite faunas of North America are dominated by the Paladin and Kaskia clades. Phylogenetic analysis of middle Carboniferous species of these clades demonstrates the close ancestral relationship between these groups. The Kaskia clade consists of eight species: K. chesterensis Weller, 1936, K. osagens...
Contexts in source publication
Context 1
... markedly than many ditomopygines, such that the axial furrows adjacent to the posterior parts of the frontal lobe embrace an acute angle of less than 45°. Pyriform frontal glabellar lobe 1.4-1.7 times longer than posterior part of glabella with only very faint indications of lateral gla- bellar furrows on most specimens. However, one specimen (Fig. 4F) shows the furrows adjacent to the axial furrows better expressed: S2 and S3 very short, narrow and inwardly directed; pair of elongate oval swellings on the posterolateral end of the composite frontal lobe probably represent L2. Pos- terior furrow S1 deep and short. Basal glabellar lobe divided into central and lateral lobes by deep ...
Context 2
... rib-like ridge and outer flattened border separated by a wide, but not un- usually deep border furrow. The ridge approximately fol- lows the lower profile of the eye, and is slightly inflated at its posterior end. Since there is a broad depression beneath the eye, the genal ridge makes a prominent and upstanding feature. The enrolled specimen on Fig. 4C shows that genal spines were probably present but the genal angle is vertically broken. Short section of posterior border furrow meets lat- eral border furrow at close to a right angle. Dorsally flat and wide border very sharply downturned at its margin to form a vertical "wall" about as deep as the border is wide. Anterior edge of ...
Context 3
... as deep as the border is wide. Anterior edge of this wall slopes towards midline along suture. Eye is underlain by a narrow convex eye socle one-third height of eye anteriorly. Eye is not high compared with that of Hentigia with visual surface three times or more as long as high in lateral view. Extent of doublure shown by exfoliated specimen (Fig. 4F), flat under border, and curving upward almost to reach furrow at base of genal ...
Similar publications
The trilobite genus Jujuyaspis Kobayashi, 1936, an index fossil of earliest Ordovician age, is recorded from the Yosimuraspis Zone of the Mungok Formation (Lower Ordovician) for the first time in Korea. The Yosimuraspis Zone comprises Yosimuraspis vulgaris Kobayashi, 1960; Jujuyaspis sinensis Zhou in Chen et al., 1980; Elkanaspis jilinensis Qian in...
Citations
... As it has been depicted by Hahn & Hahn & Brauckmann (1986) this stock of species has taxonomically been treated very differently by various authors and no general agreement seems to have been reached so far. Although apparently not considering all the assigned species in his phylogenetic analysis Brezinski (2003) Brezinski (2008). As already mentioned above, clade A represents the genus Kaskia, the morphology of which is clearly distinct from Ampulliglabella by virtue of an only moderately expanding glabella with a less defined constriction, as well as a reduced anterior border and a more semi-elliptical outline of the pygidium. ...
A newly discovered trilobite fauna from the Middle Permian Hoso-o Formation – presumably of Wordian age – of the Southern Kitakami Mountains in Northeast Japan is described and reviewed here. The fauna consists of five new species named as Cheiropyge radula n. sp., Ampulliglabella arakii n. sp., Ditomopyge benkei n. sp., Neogriffithides extremorientalis n. sp., and Weania insulana n. sp. The new taxa expand our understanding of Permian trilobites in several ways: by extending the stratigraphic range to lower levels in the Kitakami Mountains; by enhancing the data on morphologically diverse trilobite faunas in the Middle Permian; deepening the taxonomical understanding of Cheiropyge koizumii KOBAYASHI & HAMADA, 1982 and the genus Ampulliglabella KOBAYASHI & HAMADA, 1984; as well as providing valuable paleobiogeographical information. In addition, the taxon Cheiropyge koizumii from the upper Capitanian of the Southern Kitakami Mountains is revised.
... Among the 48 characters employed here (see Appendix 1), 33 were taken or modified from Lieberman 5 and 15 are new (characters 7, 9, 12, 13, 14, 22, 23, 24, 25, 26, 27, 34, 40, 41, and 42), although based on characters used in phylogenetic analyses of other trilobite groups (e.g. [35][36][37][38][39][40][41][42]. The morphological elements of the exoskeleton are shown in Fig. 7 and all morphological relations/angles used in the 15 newly proposed characters were measured as indicated in Fig. 8. ...
Metacryphaeus is a calmoniid trilobite genus from the Devonian Malvinokaffric Realm, exclusive to the Gondwanan regions. It includes eleven species, which are for the first time included here in a single phylogenetic analysis. The resulting hypotheses establish relations among the Metacryphaeus species with few ambiguities, also suggesting the inclusion of both Plesiomalvinella pujravii and P. boulei within the genus, as originally considered. The results of palaeobiogeographic analyses employing the Dispersal-Extinction-Cladogenesis (DEC) model reinforce the hypothesis that Bolivia and Peru form the ancestral home of Metacryphaeus. The radiation of the genus to other Gondwanan areas took place during transgressive eustatic episodes during the Lochkovian–Pragian. The Lochkovian dispersal occurred from Bolivia and Peru to Brazil (Paraná and Parnaíba basins) and the Falklands, and Pragian dispersal occurred towards South Africa. Dispersal events from Bolivia and Peru to the Parnaíba Basin (Brazil) were identified during the Lochkovian–Pragian, suggesting the presence of marine connections between those areas earlier than previously thought.
... Discussion. -Brezinski (2003-Brezinski ( , 2008 has summarised research on the genus Paladin Weller, 1936. He notes that Paladin is a typical genus on the North American palaeoplate during the Carboniferous, where it evolved into a number of endemic species invariably found "in deep water deposits" (Brezinski 2008: 513). ...
2015. A new, morphologically diverse Permian trilobite fauna from Oman. Acta Palae-ontologica Polonica 60 (1): 201–216. A newly discovered trilobite fauna from the early to middle Permian Qarari Unit of northeastern Sultanate of Oman is described. It comprises exceptionally complete and well-preserved examples of five proetoid species, belonging to genera typical of an eastern Tethyan region extending through southern Asia to Timor. The shallow shelf fauna compares closely with one of Artinskian age from Afghanistan. Permian species previously assigned to Paladin are here considered unrelated to this predominantly Carboniferous clade, and are placed in a new ditomopygine genus, Simulopaladin, type species Simulopaladin tridentifer sp. nov. Three other ditomopygine species are described: Hentigia ornata sp. nov., Iranaspidion elephas sp. nov., and Acanthophillipsia felicitae sp. nov. The proetid Triproetus bonbon sp. nov. is the most complete material known of a more widespread genus.
... However, in the USA, the early Late Carboniferous was associated with a renewal within the trilobite communities, rather than a modification of their subfamilial compositions. The prevalence of ditomopygines was already apparent in the late Mississippian trilobite communities composed of species of Kaskia and Paladin (Brezinski 2003(Brezinski , 2008. These trilobites were replaced during the late Bashkirian by another moderately diversified fauna composed exclusively of ditomopygines (Sevillia, Ditomopyge, and Ameura; Brezinski 1999). ...
Quantitative data reveal a complex evolution of late trilobite diversity. In the Mid- to early Late Devonian, a series of extinction events led to a drastic taxonomic impoverishment. In the Famennian, while only two orders remained, originations started to compensate still high extinction rates marking the onset of a remarkable diversification. Though interrupted by the major Hangenberg turnover, the general diversification trend accelerated in the Tournaisian whilst extinctions became modest. Originations notably diminished during the Viséan and the Serphukovian, making the diversity to step down at the level of the Frasnian. It has never been much higher thereafter, despite a profound restructuring of trilobite communities in the early Pennsylvanian permitting the progressive domination of ditomopygines. After another drop in the Kasimovian a period of stasis occurred with very low diversity levels and almost no renewal. The last diversification burst took place in the Wordian, but it ceased rapidly in the Capitanian when the degradation of environmental conditions started to inhibit originations. Thus, the extinction of the Trilobita at the end of the Permian resulted from the disappearance of merely a handful of genera.
... 24–25). This species is synonymous with Paladin mangeri Brezinski, a recently erected species known from the Morrowan Brentwood Limestone of Arkansas (Brezinski, 2008). ...
Arsenic concentrations determined on 11 lithotype samples from the Middle Pennsylvanian Breathitt Group Fire Clay coal bed, Leslie County, KY, range from 1 to 418 ppm (whole coal basis). The 11 lithotype samples, which vary in thickness from 4 to 18 cm, were sampled from a continuous 1.38 m channel sample, and were selected based on megascopic appearance (vitrain-rich versus attrital-rich).A lithotype that contains 418 ppm As is located near the top of the coal bed and is composed of 10.5 cm of bright clarain bands containing fusain that, within short distances, grade laterally into Fe sulfide bands. To determine the mode of occurrence of As in this lithotype, the coal was examined with scanning electron microscopy and analyzed by energy dispersive X-ray fluorescence.Massive, framboidal, cell filling, cell-wall replacement, and radiating forms of Fe sulfide were observed in the high As lithotype; many of the radiating Fe sulfide forms, and one of the cell-wall replacements contained As. Examination of the grains with optical light microscopy shows that the majority of radiating morphologies are pyrite, the remainder are marcasite.Selected Fe sulfide grains were also analyzed by electron microprobe microscopy. Arsenic concentrations within individual grains range from 0.0 wt.% to approximately 3.5 wt.%. On the basis of morphology, these Fe sulfides are presumed to be of syngenetic origin and would probably be removed from the coal during physical coal cleaning, thus eliminating a potential source of As from the coal combustion process. However, because the grains are radiating and have high surface area, dissolution and release of As could occur if the pyrite is oxidized in refuse ponds.
Based on cluster and correspondence analysis, Late Paleozoic trilobites are shown to display varying degrees of provincialism and cosmopolitanism through time. These distributional changes appear to coincide temporally with the closing of the Rheic Ocean and the onset and waning of the Late Paleozoic Ice Age. Early Tournaisan trilobite faunas, composed mainly of primitive phillipsid genera, display widespread distribution within ancestral deep-water environments of the Rheic Ocean. Middle to late Tournaisian through early Viséan trilobite genera were segregated into environmentally constrained endemic shelf faunas, and widespread to cosmopolitan deep-water biota. Reduced provincialism during the Serpukhovian is interpreted to have resulted from the onset of the Late Paleozoic Ice Age. Initiation of this profound global environmental perturbation is interpreted to have produced equatorially constricted climate zones and rapidly vacillating sea level and cylothemic deposits that created high levels of ecological stress within marine faunas. Early Pennsylvanian trilobite faunas exhibited weak levels of provincialism on either side of Pangea, with dominant faunal components displaying cosmopolitan tendencies. Trilobite faunas of the late Pennsylvanian were characterized by a few widespread to cosmopolitan genera, that exhibit ecologic generalist tendencies while inhabiting broad geographic and latitudinal ranges. Permian trilobites exhibit a progressive increase in provincialism through time which is interpreted to be the result of the ending of the Late Paleozoic Ice Age and the onset of greenhouse conditions.
The Loyalhanna Limestone is one of the most recognizable rock units in the Appalachian Basin. Differential weathering of its large-scale cross-bedding and massive character make this unit a widely used dimension and quarry stone. Diverging thoughts on the origin of the iconic cross-bedding have led to a long-standing debate over whether the genesis of the Loyalhanna is eolian or marine. Diagnostic bedding characters exhibited by the Loyalhanna are equivocal with most features possible in environments of both subaerial or subaqueous dune formation. Other diagnostic subaerial textures such as exposure surfaces, translatent ripple laminates, tracks, and trails are unknown in the unit. However, the Loyalhanna does contain a number of features that can be attributed to subaqueous deposition. For example, endolithic algal borings and coatings are ubiquitous. The Loyalhanna Limestone also displays a north-to-south change in lithofacies characteristics. Along its northern and eastern boundaries, the typically massive Loyalhanna is interbedded with rippled sandstone and red to variegated shale. Near its southern geographic limits, the Loyalhanna is interbedded with nodular, argillaceous, fossiliferous limestone intervals. Between these two interbedded lithofacies, the unit consists of the typical massive, cross-bedded, sandy limestone. Petrographically, the Loyalhanna contains a common microfauna of endothyrid foraminifers, and fragmented brachiopods, bryozoans, and echinoderms. A macrofauna was noted at eight locations. This fauna consists of articulated brachiopods, gastropods, bivalves, and trilobites. At other locations, comminuted megafauna assemblages are widespread. These fragmental faunas are known even in north-central and northeastern Pennsylvania. The presence of marine micro-and megafossils from throughout the Loyalhanna depositional basin and the equivocal nature of the eolian features indicate that this unit is largely if not completely marine in origin.
Significance
Shifts in biological diversity often are associated with particular anatomical traits. Anatomical data from over 300 clades of brachiopods, molluscs, arthropods, echinoderms, and chordates show that trait-based diversification shifts are common at even fairly low (genus and species) taxonomic levels. Cambrian taxa present the lone major exception. Among post-Cambrian taxa, diversification shifts correlate strongly with elevated net extinction of primitive taxa rather than elevated net speciation of derived taxa or increased morphological disparity among derived taxa. This finding emphasizes the importance of extinction in shaping morphological and phylogenetic diversity among closely related species and genera as well as suggests another way in which Cambrian evolution was unique.
