Placoid and polyodontode scales of stem chondrichthyans have been found in the early Lochkovian “Ditton

Group” of the Brown Clee Hill district, Shropshire, England and at Talgarth, south Wales. One of the forms is

assigned to a new species of Altholepis Karatajūtė-Talimaa, 1997, a genus already recognised from Lochkovian

shallow marine deposits in Celtiberia, Spain and the Northwest Territories, Canada as well as the type locality in

Podolia, Ukraine. Altholepis salopensis sp. nov. is based on small polyodontode scales with typically three to eight

high odontodes; the scale form was previously considered to belong to acanthodian “Nostolepis” robusta (Brotzen,

1934). The structure of other scales formerly assigned to “Nostolepis” robusta has led us to erect a new genus

Jolepis for this scale form, which differs from Altholepis in lacking an ordered layout of odontodes. Jolepis robusta

(Brotzen, 1934), originally (and possibly still) considered to be an acanthodian, is also known from the Baltic

countries, Russia, and northern Germany (ex erratic limestones). Scales of acanthodian Parexus recurvus Agassiz,

1845, and/or possibly from the stem chondrichthyan Seretolepis elegans Karatajūtė-Talimaa, 1968 (scales of these

two taxa are barely distinguishable), and of stem chondrichthyan Polymerolepis whitei Karatajūtė-Talimaa, 1968

are also present. Altholepis, Jolepis gen. nov., Seretolepis Karatajūtė-Talimaa, 1968 and Polymerolepis Karatajūtė-

Talimaa, 1968 are found in marine deposits elsewhere; the British occurrence of these taxa adds to the debate on

the sedimentological origins of the Lower Old Red Sandstone deposits in the Welsh Borderland. The geographic

range of several early sharks is now known to extend around the Old Red Sandstone continent and beyond.

Most people view examining fossils as a kind of hobby, and only a lucky few have managed to turn it into their profession. But is there money to be earned from it? And what benefits does the taxpayer stand to gain?

W kamieniołomie wapieni górno dewońskich w Józefce koło miejscowości Górno koło Kielc w Górach Świętokrzyskich stwierdzono współwystępowanie węglowodorów i siarczków żelaza i miedzi w spękaniach w strefie uskokowej. Węglowodory występują także w formie rozproszonej, plamiście w otaczających wapieniach nadając im czarną barwę oraz wzdłuż płaszczyzn ich warstwowania. Współwystępowanie węglowodorów i siarczków metali sugeruje ich wspólną genezę i migrację z głęboko położonego źródła. Skałami macierzystymi, mogły być czarne łupki występujące w utworach syluru i ordowiku oraz na pograniczu dewonu dolnego i środkowego wyróżniane jako wzbogacony w metale „poziom rudonośny”. Zwrócono uwagę, że nośnikiem metali mogły być związki metaloorganiczne.

Placoderms are the iconic prehistoric fish from the Devonian. Recent 3D scans have revealed their astonishing anatomical similarities with us humans.

Here we use synchrotron tomography to characterise dental vasculature in the oldest known tooth-bearing

sharks, Leonodus carlsi Mader, 1986 and Celtiberina maderi Wang, 1993. Three dimensional reconstruction

of the vascular system and microstructure of both taxa revealed a complex and dense network of canals, including

horizontal, ascending and secondary bifurcated canals, as well as histological features consistent with

an osteodont histotype. However, L. carlsi and C. maderi also exhibit significant morphological differences,

showing Leonodus a typical diplodont tooth morphology with a linguo-labially elongated base, that contrast

with Celtiberina’s teeth that show a single conical cusp curved lingually with a week developed flat base mesio-

distally extended, perhaps reflecting distant relationship. These data are compatible with a pre-Devonian

diversification of the two main tooth types traditionally recognised in Palaeozoic sharks (i.e., “cladodont” vs

“diplodont”). Finally, our data demonstrate that existing dental classification schemes based on styles of vascularisation

are over-simplified, especially when Palaeozoic taxa are considered.

A huge isolated accumulation, more than 3 m thick and 10 m wide, of densely packed, uncrushed brachiopods has been found in Józefka Quarry within the Middle/Upper Devonian Szydłówek Beds deposited in a relatively deep environment of an intrashelf basin (Kostomłoty facies zone, western Holy Cross Mountains, Poland). The low-diversity assemblage is strongly dominated by the atrypide Desquamatia globosa jozefkae Baliński subsp. nov. and, to a lesser degree, by the rhynchonellide Coeloterorhynchus dillanus (Schmidt, 1941), which constitute 72.8% and 22.1% of the fauna, respectively. Less frequent are specimens representing the genera Hypothyridina, Schizophoria and Phlogoiderynchus. According to the conodont fauna found within the coquina bed, the stratigraphic position of the shell accumulation is close to the Givetian/ Frasnian boundary. The brachiopods are associated with numerous crinoids and less frequent bryozoans, receptaculitids (Palaeozoic problematica), sponges and solitary corals. Although it is difficult to entirely exclude the autochthonous nature of the brachiopod coquina member, its allochthonous origin and redeposition of the brachiopod shells to the deep basin by gravity flows is much more probable. Such conclusion is supported by the following facts: (1) the position of the complex in a succession of deep-marine basinal facies impoverished in oxygen; (2) its lateral thinning-out and composite internal stratification; (3) the lensshaped geometry of the coquina bed in the section perpendicular to the bedding dip; (4) high variability of the sediments preserved within the shells; and (5) the preferred orientation of the shells. The brachiopods mixed with crinoidal debris were probably transported by low-velocity, high-density, gravity-induced debris flows. Lack of fossils typical of the Middle Devonian shallows, such as massive stromatoporoids, amphiporoids and tabulates, indicates that the source area of the bioclastic material was not located in the shallowest part of the shelf, but most probably on a submarine sea-mount to the north of present-day Józefka, as suggested by earlier investigators. The triggering mechanism of the allochthonous deposition was an earthquake rather than storm activity. The enormous thickness of the brachiopod complex is probably caused by the sinking of bioclastic material, transported in succeeding depositional multi-events, in a soft, muddy bottom, typical of the Szydłówek Beds deposition.

Krajowa baza zasobowa dolomitów jest duża. Ich łączne zasoby bilansowe, udokumentowane w 62 złożach - wykazywanych w aktualnych statystykach zasobów kopalin - wynoszą 1 500 mln t. Mimo tego występuje deficyt wysokiej jakości tzw. dolomitów konwertorowych, które mają zastosowanie do produkcji materiałów ogniotrwałych. Dla tego celu wykorzystywane są od wielu lat dolomity triasowe ze złóż Brudzowice i Ząbkowice Śląskie I, z regionu śląsko-krakowskiego. Do innych potencjalnie interesujących złóż tego regionu, ze względu na charakter i właściwości dolomitów, należy złoże Libiąż. Wątpliwa, choć niewykluczona wydaje się możliwość wykorzystania dolomitów ze złóż Nowa Wioska i Stare Gliny. Wymaga to jednak przeprowadzenia bardziej dokładnych badań ich składu chemicznego i podatności do spiekania. Jak dotąd bowiem, dolomity z tych złóż są rozpoznane i aktualnie eksploatowane na znaczną skalę przede wszystkim dla potrzeb drogownictwa i budownictwa. Niestety, pogarszająca się jakość dolomitów zalegających w innym, dużym i udostępnionym złożu tego regionu - Żelatowa - była przyczyną zaniechania wykorzystania tej kopaliny do produkcji materiałów ogniotrwałych. Spośród złóż rezerwowych najkorzystniejszymi właściwościami wyróżniają się cztery: Chruszczobród, Chruszczobród I, Chruszczobród 2 i Libiąż Wielki. Przeprowadzona analiza wskazuje także na możliwość wykorzystania dla celów przemysłu materiałów ogniotrwałych kopalin ze złóż Winna i - w mniejszym stopniu - Radkowice-Podwole. Wymaga to jednak przeprowadzenia bardziej szczegółowych badań ich składu chemicznego i struktury, a zwłaszcza określenia wielkości ziaren. Odrębne zagadnienie stanowi kwestia wykorzystania marmurów dolomitowych ze złóż regionu dolnośląskiego. Tradycyjnie uważa się, że są one nieprzydatne do produkcji materiałów ogniotrwałych z uwagi na grube uziarnienie. Kopalina ta występuje jednak w kilku odmianach, reprezentując również struktury drobno i średniokrystaliczne. Najczystsze i najbardziej drobnoziarniste odmiany mogą być interesujące do produkcji materiałów ogniotrwałych. Wymaga to jednak prowadzenia selektywnej ich eksploatacji.

Very rare chondrichthyan spines from the Famennian (Upper Devonian) of European Russia are referred here to ctenacanthiforms, euselachians and a chondrichthyan group of uncertain systematic position. Ctenacanthus Agassiz, 1837 is recorded from the lower and middle Famennian of the central and north-western parts of the area. Sculptospina makhlaevi Lebedev gen. et sp. nov. originates from the lower Famennian of the Lipetsk Region. The holotype of ‘Ctenacanthus’ jaekeli Gross, 1933 and a new specimen from the upper Famennian of the South Urals are shown to belong to the same taxon, which is transferred to Acondylacanthus St. John and Worthen, 1875. New specimens of Tuberospina nataliae Lebedev, 1995 from the upper Famennian of Central Russia are described in detail. The newly presented material increases our knowledge of the composition of Famennian marine assemblages from the East European Platform. It is suggested that these assemblages may be classified as chondrichthyan-dominated and dipnoan-dominated. Hypothetically, after the end- Devonian Hangenberg extinction event, which affected numerous secondary consumers in vertebrate communities, some chondrichthyan groups could have encroached to take advantage of previously occupied ecological niches. Ctenacanthus, as well as Acondylacanthus and Amelacanthus survived the end-Devonian mass extinction to continue into the Carboniferous.

The Shotori Range of east-central Iran (east of Tabas) has yielded Famennian ammonoid assemblages dominated by the family Sporadoceratidae. Four genera Maeneceras Hyatt, 1884, Iranoceras Walliser, 1966, Sporadoceras Hyatt, 1884 and Erfoudites Korn, 1999 are represented. The conodont assemblage of one sample containing Iranoceras revealed an Upper marginifera Zone age. The ammonoid assemblages are characterised by comparatively large specimens; they reach conch diameters of 300 mm (including the body chamber) and the mean size is larger than 100 mm. The preservation of the material from the Shotori Range and size comparison with sporadoceratid assemblages from the Anti-Atlas of Morocco and the Rhenish Mountains of Germany suggest that hydraulic sorting has resulted in a bias towards large conchs, explaining the size distribution, rather than latitudinal differences. The new species Maeneceras tabasense is described; the genus Iranoceras is revised with a new description of the two species Iranoceras pachydiscus (Walliser, 1966) and Iranoceras pingue (Walliser, 1966).

The Cleveland Shale fauna represents a unique view of the time after a major Devonian extinction event

(Frasnian–Famenian) with the recovery of arthrodires (Placodermi) best represented by this most specious

North American fauna. This time was followed by an additional event (Hangenberg Biocrisis) leading to the

extinction of arthrodires (and all other placoderms). An understanding of the diversity and interrelationships of

North American arthrodires can aid our understanding of this critical time in vertebrate evolution. A new aspinothoracid

arthrodire Hlavinichthys jacksoni gen. et sp. nov. is described from the Late Devonian of northern

Ohio, U.S.A., which adds to our knowledge of this group. It provides a point of comparison to other members

of the fauna whose interrelationships are poorly known. A phylogenetic analysis supports an assignment of

Hlavinichthys jacksoni gen. et sp. nov. among the aspinothoracid arthrodires. This work has drawn attention to

the continued need for descriptive and phylogenetic analyses of this unique fauna. Decades old species descriptions

need revision along with preparation and description of new taxa. The work on Hlavinichthys jacksoni

gen. et sp. nov. here is one step in that process.

Six enigmatic fossils from the Famennian (Devonian) Cleveland Shale in Ohio, U.S.A., are interpreted here as

arthrodiran (Placodermi) egg cases. Recognition as egg cases is confirmed based on the observation of layered

collagen fibers. The presence of a tuberculated bone fragment preserved within one case confirms a vertebrate

source. The nature of the tubercles and the unique morphology of the egg cases supports the interpretation of

an arthrodiran source. Reports of Devonian egg cases are limited to either assumed chondrichthyan producers

or a putative ‘egg sac’ with a morphology atypical for any vertebrate. The Cleveland Shale egg cases thus

represent the first record for a non-chondrichthyan producer. Among placoderms, behaviors of a pelagic life

style with obligate nesting sites, reef fishes with live birth, and estuarine and fluvial nurseries, along with eggcase

oviparity testifies to the diversity of reproductive strategies. As with modern fishes these strategies may

be ecologically driven and the derived and variable reproductive biology of extant chondrichthyans is actually

a primitive condition among gnathostomes. One consequence of the diversity of reproductive strategies (dependent

on the topology of relationships) is the independent origin of internal fertilization within placoderms,

possibly suggesting external fertilization as the primitive gnathostome reproductive mode.