8 research outputs found
Diversity of the Schizophoria lineage (Brachiopoda: Orthida) in the Lower and Middle Devonian of Poland and adjacent areas
Latest Cretaceous leaf floras from southern Poland and western Ukraine
Latest Cretaceous (Campanian to Maastrichtian) leaf fossil assemblages are described from 33 exposures ranging from
the southern border of the Holy Cross Mountains (southern Poland) through the Roztocze region (south−eastern Poland)
to the vicinity of L’viv (western Ukraine). The fossil assemblage is allochthonous, preserved in marine sediments, yet
complete compound leaves strongly argue for the transport having been short. Krasnobród and Potelych (Potylicz) are the
richest localities; both are late Campanian. The abundance of angiosperm remains in this period is explained by a marine
lowstand resulting in nearby emergent vegetated areas. The flora was composed of ferns (three species), conifers (five
species, including the commonest Geinitzia reichenbachii), dicotyledons (seventeen taxa; Debeya paulinae sp. nov., two
other species of Debeya, and Rarytkinia polonica being the most frequent), and a single presumed monocotyledon. The
eudicot clade is formalised as supersubclass Eudicotyledoneae Doyle and Hotton ex Halamski, herein. The approximately equal abundance of serrate/lobate and entire−margined dicots attests to an intermediate character of the flora between more thermophilic and polar vegetation. The material may have come from at least two communities: xeromorphic
mixed Debeya−conifer forests and platanoid−Lauraceae forests growing in disturbed environments along rivers. The assemblage is most similar to approximately coeval floras from Westphalia and the Netherlands
Thomasaria vs. Pyramidalia conundrum in Devonian brachiopod systematics solved: An argument to formalize epitypification under the ICZN
Pyramidalia is a brachiopod genus with Spirifera simplex as the type species. Imprecise diagnosis and misidentification of the material studied in the original description resulted in a plethora of interpretations (a valid genus belonging either to the order Spiriferida or to the Spiriferinida; synonym of the spiriferide Thomasaria; synonym of Squamulariina or Cyrtinaella, both spiriferinides). To address this problem we designated the specimen GSM 6915 from Wolborough quarry near Newton Abbot (Devon, England; Givetian) as the lectotype of Spirifera simplex. We examined microstructure and internal characters of a topotypic specimen and found out that Spirifera simplex has an impunctate shell and is thus a spiriferide, not a spiriferinide. No significant differences in morphology or internal characters of Thomasaria and Pyramidalia can be found, so the latter is interpreted as a junior subjective synonym of the former. The procedure used in the present analysis is equivalent to the epitypification provided for in the ICN; formalisation of a similar procedure under the ICZN is recommended
Late Cretaceous mega-, meso-, and microfloras from Lower Silesia
Late Cretaceous plants from the North Sudetic Basin (Lower Silesia, south-western Poland) are reviewed on the basis of
megaflora from 17 localities (270 identifiable specimens), mesoflora from two localities, and microflora from four localities.
Major sites are Rakowice Małe and Bolesławiec. Eight megafloral assemblages are distinguished (Assemblage 1, Turonian;
Assemblages 2, 3, lower–middle Coniacian; Assemblages 4, 5, upper Coniacian?–lower Santonian?; Assemblages 6–8,
lower–middle Santonian); the bulk of the palaeoflora is from Assemblages 4–6 and 8. Megaflora consists of 29 taxa (6 ferns,
4 conifers, and 19 angiosperms). Geinitzia reichenbachii is the most common species. Dryophyllum westerhausianum
(Richter, 1904) Halamski and Kvaček comb. nov. is a trifoliolate leaf re-interpreted as a representative of Fagales. Three
species of Dewalquea are distinguished: Dewalquea haldemiana, Dewalquea insignis, and Dewalquea aff. gelindenensis.
Platanites willigeri Halamski and Kvaček sp. nov. is characterised by trifoliolate leaves, the median leaflet of which is
ovate, unlobed, with a serrate margin, and cuneate base. Palaeocommunities inferred from the megafossil record include:
a back swamp forest dominated by Geinitzia, with abundant ferns; a Dryophyllum-dominated riparian forest; a forest with
Dewalquea and Platanites willigeri possibly located in the marginal part of the alluvial plain; dunes with D. haldemiana and
Konijnenburgia; a fern savanna with patches of Pinus woodlands. Palynoassemblage A from the Nowogrodziec Member,
studied mostly at Rakowice Małe and Żeliszów, consists of 126 taxa, including 105 terrestrial palynomorphs (54 bryophyte,
lycophyte, and pteridophyte spores, 16 gymnosperms, 35 angiosperms). The mega- and mesofossil records are dominated
by angiosperms; the palynoassemblages are dominated by ferns. Palaeocommunities represented solely by the microfossil
record are halophytic (with Frenelopsis and unconfirmed presence of Nypa) and pioneer vegetation. Palaeocommunities
are intermediate in general character between those pre-dating the Cretaceous Terrestrial Revolution and modern, angiosperm-
dominated vegetation. In comparison to older plant assemblages from contiguous areas laurophylls are much rarer;
this might correspond to a real phenomenon of exclusion of lauroids from Santonian riparian forests. The studied assemblage
is more similar to younger palaeofloras than to older ones; this might be interpreted as stabilisation of communities
after a period of pronounced change related to the rise to dominance of the angiosperms. In contrast to widespread endemism
among vertebrates of the European Archipelago, the plant cover consists mostly of species that are widely distributed