3,289 research outputs found
A new ophiuroid from the Maastrichtian type area (Late Cretaceous, SE Netherlands, NE Belgium)
From the Kunrade limestone facies and from the Emael, Nekum and Meerssen Members of the Maastricht Formation (late Maastrichtian) in the type area of the Maastrichtian Stage, a new genus and species of ophiuroid, Felderophiura vanderhami n. gen., n. sp., is described and illustrated. In addition to numerous disarticulated ossicles of disc and arms some twenty more or less complete specimens and several dozens of arm fragments are available for study; occurrences like these have recently proved to be comparatively common in the Maastrichtian type area. A brief discussion of ophiuroid remains collected from Campanian and Maastrichtian strata in this area is added
Campanian-Maastrichtian pelagic crinoids from NE Belgium and SE Netherlands: preliminary observations
During recent years unexpectedly rich and diverse faunules of diminutive, pelagic crinoids of the order Roveacrinida SIEVERTS-DORECK in MOORE, LALICKER & FISCHER, 1952 have been collected from early and late Campanian and late Maastrichtian strata in the Maastrichtian type area (southern Limburg, The Netherlands, and contiguous areas). Most, if not all, of these forms appear to be still undescribed. Occurrences known to date are briefly discussed; a taxonomic study with detailed descriptions of the various species is under way
The ichnofossil genera <i>Radulichnus</i> and <i>Renichnus</i> in the Maastrichtian of The Netherlands and Belgium
The tuffaceous chalk facies (biocalcarenites) of the Maastricht Formation (Late Maastrichtian) in its type area (SE Netherlands, NE Belgium) has yielded numerous ichnofossil taxa; however, the genera Radulichnus and Renichnus were not yet recorded. Here, examples of these two taxa are described and illustrated. Radulichnus traces are left on a lithified substrate by the radula of certain gastropod and/or polyplacophoran (chitonid) molluscs, while Renichnus are etched traces of shells of vermetid gastropods. Vermetids from the Maastricht Formation are briefly discussed; an example of Vermetus clathratus BINKHORST, 1861 is illustrated. In addition, the ichnofossil Centrichnus eccentricus BROMLEY & MARTINELL, 1991, the byssal etching trace of anomiid bivalves which bears a superficial resemblance to Renichnus, is also documented
Periproctal plating in the echinoid <i>Coenholectypus larteti</i> (Cenomanian, Sultanate of Oman)
A specimen of the holectypid echinoid Coenholectypus larteti (COTTEAU, 1869), from the 'Echinoid Marker Bed' of Member C (Natih Formation, uppermost Middle Cenomanian, Cretaceous) at Jebel Madamar (central Oman Mountains, Sultanate of Oman), preserves periproctal plating. This is only the second example of such plating in the genus Coenholectypus. Previous records of periproctal and/or peristomial plating in holectypoids and other irregular echinoids are listed and briefly discussed
Ophiurites eocaenus Leriche, 1931 (Ophiuroidea, Eocene, NW Belgium) revisited
The ophiuroid species Ophiurites eocaenus LERICHE, 1931 from Eocene ("Paniselian") strata in northwestern Belgium is redescribed on the basis of the four specimens that constitute the type lot from Zeebrugge and two additional specimens on a slab recently collected from the beach near Cadzand (province of Zeeland, The Netherlands), some 15 km north of Zeebrugge. Details of disc and arm plating are better preserved in the Cadzand specimens than in the type lot. The species cannot be assigned to Stegophiura MATSUMOTO, 1915; it is here tentatively referred to Ophiozona LYMAN, 1865 and compared with other Tertiary species from NW Europe and elsewhere. Some remarks on the stratigraphic provenance of this species are added
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