Placoderms from the Lower Devonian "placoderm sandstone" of the Holy Cross Mountains, Poland with biostratigraphical and palaeobiogeographical implications

The siliciclastic sequence of the Lower Devonian of the southern part of the Holy Cross Mountains in Poland is renown for abundant vertebrate fossils, including ostracoderm, sarcopterygian, acanthodian, chondrichthyan, and placoderm remains. Study of the vertebrate assemblage from the "placoderm sandstone" from Podlazie Hill in the Holy Cross Mountains reveals that the remains belong to Kujdanowiaspis sp. among other unspecified actinolepids and brachythoracids. The Polish actinolepid material is characterised by sizes bigger than those of the Podolian specimens; this may be related to geographic variation. Owing to the proximity between Podolia and Holy Cross Mountains we suggest that Kujdanowiaspis sp. from the Holy Cross Mountains may be a refugee of some species of Kujdanowiaspis from the Lochkovian-Pragian of Podolia and/or from Spain. Some anterolateral plates provisionally assigned to Arthrodira indet. probably represent a new genus due to the high overlapping surface for median dorsal and anteroventrolateral plates.The Podłazie locality was examined during the fieldwork in 2011–2012 financed by the Ministry of Science and Higher Education (grant IP2010 041470 to PS)

Revision of the Late Devonian ptyctodonts (Vertebrata, Placodermi) from southern Poland

New studies on Frasnian ptyctodonts, including the revision of historic material in addition to the description of new material, have resulted in the detailed description of two species of Ptyctodus (Ptyctodus obliquus, Ptyctodus kielcensis), eight indeterminate specimens of Ptyctodus sp. from the Holy Cross Mountains and two specimens from DÄbnik near Kraków, four indeterminate specimens of Rhynchodus sp., and two specimens of Ptyctodontidae gen. et sp. indet. from the Holy Cross Mountains. One of the described species (P. kielcensis) appears to be endemic for the Holy Cross Mountains region. Based on general knowledge of the Frasnian stratigraphy of the Holy Cross Mountains and on the conodont material obtained from the fragments of the sediments attached to specimens, it was possible to define the predetermined subdivision of the Frasnian as ranges of conodonts and the fauna to be placed within conodont zones. Previously only antiarchs, bottom-feeding placoderms, had been recovered from the Lower and Upper Kellwasser horizons from this area (PÅucki); thus, the occurrence of ptyctodonts represents an additional placoderm taxon. This work describes the first placoderm remains from DÄbnik near Kraków, which also represent the first described placoderms from an area other than the Holy Cross Mountains

Extreme lower jaw elongation in a placoderm reflects high disparity and modularity in early vertebrate evolution

Jaws are a key vertebrate feature that arose early in our evolution. Placoderms are among the first jawed vertebrates; their fossils yield essential knowledge about the early diversification of gnathostome feeding strategies, diets and modularity. Modularity can be expressed through disproportional lengths of lower and upper jaws as in swordfish or halfbeaks. Alienacanthus malkowskii is an arthrodire from the Famennian of Morocco and Poland, whose most remarkable feature is its lower jaw, which is twice as long as the skull. This is the oldest record of such extreme jaw elongation and modularity in vertebrates. The gnathal plates of Alienacanthus possess sharp, posteriorly recurved teeth that continue anterior of the occlusion in the inferognathals. The dentition suggests a catching and trapping live prey function, and the jaw occlusion is unique among placoderms. This armoured ‘fish’ expands the morphological and ecological diversity during one of the first radiations of jawed vertebrates with a combination of features so far unrecorded for arthrodires

A large Late Devonian arthrodire (Vertebrata, Placodermi) from Poland

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

Placoderms from the Early Devonian “placoderm sandstone” of the Holy Cross Mountains, Poland with biostratigraphical and palaeobiogeographical implications

The siliciclastic sequence of the Lower Devonian of the southern part of the Holy Cross Mountains in Poland is renown for abundant vertebrate fossils, including ostracoderm, sarcopterygian, acanthodian, chondrichthyan, and placoderm remains. Study of the vertebrate assemblage from the “placoderm sandstone” from Podłazie Hill in the Holy Cross Mountains reveals that the remains belong to Kujdanowiaspis sp. among other unspecified actinolepids and brachythoracids. The Polish actinolepid material is characterised by sizes bigger than those of the Podolian specimens; this may be related to geographic variation. Owing to the proximity between Podolia and Holy Cross Mountains we suggest that Kujdanowiaspis sp. from the Holy Cross Mountains may be a refugee of some species of Kujdanowiaspis from the Lochkovian–Pragian of Podolia and/or from Spain. Some anterolateral plates provisionally assigned to Arthrodira indet. probably represent a new genus due to the high overlapping surface for median dorsal and anteroventrolateral plates

The Late Devonian placoderm Aspidichthys Newberry, 1873 from the Holy Cross Mountains, Poland

The reported placoderm remains from the Holy Cross Mountains, Poland, belongto the species Aspidichthys ingens Koenen, 1883. This study focuseson the material described in the past from Wietrznia Quarry but the newspecimens were also collected form Kowala and Płucki localities. Allspecimens presented here differ from others described in the past, mainlyby having smaller tubercles and possessing a distinctive crest in the anteriormedian part of the median dorsal plate, but did not allow the erection of anew taxon. Based on conodont assemblage, all specimens are attributed to aFrasnian age. Aspidichthys occurs in the middle to the upper partof the Frasnian (Palmatolepis punctata to P. linguiformisconodont zone) and is not found in the Famennian boundary. Describedspecimens also occur in a stepwise deepening environment causedby local synsedimentary tectonics

The Late Devonian placoderm <i>Aspidichthys</i> Newberry, 1873 from the Holy Cross Mountains, Poland

The reported placoderm remains from the Holy Cross Mountains, Poland, belong to the species Aspidichthys ingens Koenen, 1883. This study focuses on the material described in the past from Wietrznia Quarry but the new specimens were also collected form Kowala and Płucki localities. All specimens presented here differ from others described in the past, mainly by having smaller tubercles and possessing a distinctive crest in the anterior median part of the median dorsal plate, but did not allow the erection of a new taxon. Based on conodont assemblage, all specimens are attributed to a Frasnian age. Aspidichthys occurs in the middle to the upper part of the Frasnian (Palmatolepis punctata to P. linguiformis conodont zone) and is not found in the Famennian boundary. Described specimens also occur in a stepwise deepening environment caused by local synsedimentary tectonics

Environmental differentiation reflected in the vertebrate fauna diversity in the Lower Devonian of the Holy Cross Mountains, Poland

The Lower Devonian of the Holy Cross Mountains is well-known in the field of vertebrate palaeontology but remains unrecognized as regards palaeoenvironmental reconstructions. We therefore analysed the spatial distribution and relative abundance of fossil vertebrates in this area within one time interval. The fauna from an Early Devonian (Emsian) siliciclastic bone-bearing breccia (the “Placoderm Sandstone”) exposed in four sections of the Łysogóry region and five sections of the Kielce region was analysed with respect to the frequency of the remains and their taxonomic affinity. The relative abundances of agnathans, acanthodians, placoderms, osteichthyans and chondrichthyans suggest more open marine conditions in the Łysogóry region and more terrestrial-influenced in the Kielce region during the Emsian. The results show that the average agnathan and acanthodian content of the Łysogóry region is significantly larger than that in the Kielce region. On the other hand, there are relatively fewer osteichthyans in the Łysogóry region and a significantly higher proportion of bony fishes was recorded in the fauna of the Kielce region. Placoderms are characterized by their generally similar frequency in both regions and from site to site in each of them, though a greater abundance was noted from the Kielce region. Likewise differences in the proportions of particular groups in the Kielce region suggest a large variety of marginal-marine environments under the influence of factors that might have included marine currents and variable conditions around a river mouth

GEOTOURISM IN TOURISTIC REGIONS OF SOUTH-EAST POLAND - ADJUSTMENT OF GEOTOURIST OBJECTS FOR SUSTAINABLE TOURISM

Zróżnicowanie budowy geologicznej, bogactwo form geomorfologicznych, minerałów, nagromadzeń skamieniałości, śladów procesów geologicznych czynią obszar Polski Południowo-Wschodniej szczególnie atrakcyjnym dla rozwoju geoturystyki. Cechy geoturystyki, takie jak walory poznawcze, edukacyjne, dbałość o ochronę środowiska, dążenie do dywersyfikacji gospodarki i aktywizacji lokalnych społeczności, odzwierciedlają założenia turystyki zrównoważonej. Wykreowanie ciekawych produktów geoturystycznych poprzez odpowiednie przystosowanie obiektów geologicznych do ruchu turystycznego może wpłynąć na podniesienie konkurencyjności i atrakcyjności, a tym samym poprawę sytuacji gospodarczej regionu.Diversification of geological structure, variety of geomorphological forms, minerals, fossil accumulations, evidence and traces of geological processes make the area of South-East Poland particularly attractive for the geotourism development. Features of geotourism such as cognitive and educational values, environmental protection, aspiration to diversification of economy and the local society activation reflect the assumptions of sustainable tourism. Creation of interesting geotouristic products through proper adaptation of geological facilities to tourism needs could improve the competitiveness and attractiveness of the region as well as its economic situation

New cranial material of the acanthothoracid placoderm Palaeacanthaspis vasta from the Lower Devonian of Podolia-phylogenetic and taxonomic significance

The Early Devonian vertebrates of Podolia in Ukraine are well known thanks to the material of the basal arthrodire placodenn genus Kujdanowiaspis, originally mentioned by Brotzen in 1934. The anatomical fame of Kujdanowiaspis brought by Erik Stensio almost eclipsed the presence of the acanthothoracid placoderm Palaeacanthapsis vasta in the underlying beds, with the original material of P. vasta being less well preserved and abundant than that of Kujdanowiaspis. Here we describe a newly discovered specimen of the acanthothoracid P. vasta from the Lochkovian of Podolia (Ukraine). The specimen, although incomplete, is very well preserved in three dimensions and allows a thorough description of its external morphology, which is compared to that of Romundina stellina and other well-known Acanthothoraci. A phylogenetic analysis is performed and the acanthothoracid nature of Palaeacanthaspis is confirmed. However, the position of Palaeacanthaspis within the Acanthothoraci remains uncertain, and its resemblance with Romundina could be due to either synapomorphies or symplesiomorphies. Similarities and differences between the two forms are exposed, and lead to the lack of synonymy at the specific level. Generic synonymy is also questioned for the first time but remains equivocal