Psilophyton szaferi sp. nor. from the Lower Devonian of the Holy Cross Mountains. Poland

<em>Philophyton szaferi</em> sp. nov. belonging to the <em>Trimerophytina</em> was found in the Lower Devonian (Emsian) in the bore-hole Modrzewie 2A near Bostów in the Holy Cross Mountains (Gory Świętokrzyskie). The axes are sterile and fertile. their branching is dichotomous, unequally dichotomous and unequally dochotomous where the wider branch tends to form the main axis. The majority of axes branch in one plane, some in different planes; they show on their surface irregularly distributed enations in the form of rounded swellings. Some of them continue downwards as protruding ridges forming a characteristic longitudinal pattern. The apices of sterile axes are forking. Fertile axes end in clusters of fusiform. upright sporangia, arranged in pairs. The vascular strand shows protoxylem inside and metaxylem outside. Tracheids possess scalariform thickenings and what appear to be small pits between them. The systematic position of the plant and its position in the evolutionary sequence leading to megaphyllous leaves is discussed.

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Note on the morphology and systematic position of Alkenopterus burglahrensis (Chelicerata: Eurypterida: Eurypterina) from the Lower Devonian of Germany

PalZ ◽

10.1007/s12542-013-0189-x ◽

2013 ◽

Vol 88 (2) ◽

pp. 223-226 ◽

Cited By ~ 1

Author(s):

Markus Poschmann

Keyword(s):

Lower Devonian ◽

Systematic Position

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New finds of Drepanophycus spinaeformis Göppert from the Lower Devonian of Scotland

Transactions of the Royal Society of Edinburgh Earth Sciences ◽

10.1017/s0263593300013997 ◽

1984 ◽

Vol 75 (4) ◽

pp. 353-363 ◽

Cited By ~ 38

Author(s):

R. J. Rayner

Keyword(s):

Lower Devonian ◽

Systematic Position

ABSTRACTDrepanophycus spinaeformis Göppert is a long ranging Devonian plant. Although reported from numerous localities, it is far from well understood. Observations on specimens from the Emsian Strathmore Group of Scotland have revealed variation in forms of branching including root-like axes on branches interpreted as rhizomes. The anatomy of the xylem is described from uncompressed pyrite permineralisations. Cuticle characteristics are also described and discussed. The systematic position of the plant is debated since, although the morphology of the leaves, leaf traces, roots and xylem indicate an affinity with the lycopods, there is some doubt as to whether sporangial position permits inclusion in this group.

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Redescriptions of some Lower Devonian gastropods from Tennessee currently considered to be platyceratids

Journal of Paleontology ◽

10.1017/jpa.2016.50 ◽

2016 ◽

Vol 90 (2) ◽

pp. 195-210 ◽

Cited By ~ 1

Author(s):

John A. Harper

Keyword(s):

Lower Devonian ◽

Systematic Position ◽

Type Specimens ◽

Lower Carboniferous ◽

New Family ◽

Juvenile Specimen

AbstractThree genera of gastropods described from the Lower Devonian Rockhouse Formation of Hardin County, Tennessee, currently are considered to be junior subjective synonyms ofPlatyceras(Visitator) Perner, 1911. Evaluation of the type specimens of these genera as well as types of two other gastropods from the same formation reveals the following:Platyostoma quadrangulare(Dunbar, 1920) is the only platyceratid gastropod among them;Saffordella tennessensisDunbar, 1920 has a selenizone above midwhorl so it is an eotomarioidean belonging to the Gosseletinidae;Aulopea nelsoniDunbar, 1920 and the lectotype ofDistemnostoma princepsDunbar, 1920 each has a broad subsutural sinus on the upper whorl surface similar to the Omphalotrochidae, as well as a basal sinus similar to certain primitive caenogastropods, so their systematic position is uncertain; I considerHolopea planidorsataDunbar, 1920 to be a juvenile specimen ofD. princeps; the fragmentary paralectotype ofD. princepspossibly represents a gerontic form ofDistemnostoma curtumDunbar, 1920, which possesses a well-developed selenizone on an upwardly projecting shoulder at the edge of the upper whorl surface. BecauseD. curtumappears to be unrelated toD. princeps, the genotype ofDistemnostoma, I propose the new generic nameOmocordellaforD. curtum. The new family Micromphalidae is erected to include OrdovicianSlehoferiaRohr and Fryda, 2001, lower CarboniferousMicromphalusKnight, 1945, andOmocordellan. gen.

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