And SE Netherlands: K/T Boundary Extinction
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Contr. Tert. Quatern. Geol. 29(3-4) 73-137 3 tabs, 9 pis. Leiden, February 1993 Danian Serpulidae and Spirorbidae from NE Belgium and SE Netherlands: K/T boundary extinction, survival, and origination patterns ManfredJäger Rohrbach Zement Dotternhausen, Germany SE Netherlands: K/T extinction, survival, and Jager, Manfred. Danian Serpulidae and Spirorbidae from NE Belgium and boundary — Contr. Tert. 3 tabs, 9 pis. Leiden, February 1993. origination patterns. Quatern. Geol., 29(3-4): 73-137, the Palaeocene Geulhem Member Formation) Twenty-two serpulid and spirorbid species and subspecies from early (Danian) (Houthem illustrated, discussed in detail and to the following Cycloserpula, as exposed in the type area of the Maastrichtian Stage are assigned genera: Rotularia, Metavermilia ?, Placostegus, Neomicrorbis, Bipygmaeus, Pileolaria ? and Neodexiospira ?. Three Serpula?, Cementula, Ditrupa, Pyrgopolon, Rotularia tobar and R. (R.) tobar vroenhovensis, while additional new new subspecies are erected, viz. Neomicrorbis parietalis jagti, (R.) gracilis Within the Geulhem Member there but moderate of described in nomenclature as are known. are species are necessity open they poorly changes in the serpulid/spirorbid faunas, which result mainly from differences between hard and soft substrates. Of twenty-two recorded from the classic Danian ofDenmark, which corroborates the correlation ofthe Geulhem (sub)species sevenhave previously been Member with the while two show differences at the subspecies level. Although data are at present insufficient to type Danian, slight middle and determine precisely the position ofthe Geulhem Member within the type Danian succession, faunal relationships suggest a Danian for this member. A of Danian faunas with Maastrichtian late Danian rather than an early age comparison serpulid/spirorbid world shows that the former in fact a slightly impoverished ones from the Maastricht area as well as from other parts of the represent the K/T these either shallow and Thirteen and became extinct at or near boundary: were fauna ofMaastrichtian type. genera subgenera substrate, or and few Most warm water forms which for fixation needed a large genera subgeneracomprising only species. (sub)genera and above the crossed the K/T boundary, the majority (seventeen to twenty-four) with different species below boundary, some (eight) the with identical few and the Danian/Palaeocene. species. Comparatively (seven) genera subgenera originated during Generally, which the are similar those described for other benthic suspension/detritus feeders, on extinction, survival and origination patterns to K/T boundary event had only a limited influence. — NE SE Netherlands, new Key words Serpulidae, Spirorbidae, Maastrichtian, Danian, K/T boundary, Belgium, taxa. Dr M. Jager, Rohrbach Zement, D(W)-7466 Dotternhausen, Germany. Collins added few others. The two Contents (1988, fig. 1) a most important localities in the environs of Introduction 73 p. Maastricht the former Curfs Geulhem are quarry at Systematic descriptions p. 74 (now Ankersmit Holding BV) and the temporary Discussion 110 p. Canal Vroenhoven- sections along the Albert near 110 Comparisons p. Riemst between the Vroenhoven and Veldwezelt K/T extinction, survival and boundary origi- The section the Ankersmit bridges. at quarry was nation events p. 112 designated stratotype of the Geulhem Member 115 Acknowledgements p. (Houthem Formation) by Felder (1975); this will References 115 p. presumably remain well exposed through future quarrying. However, only eight metres of Danian Introduction in strata are exposed there, this contrast to c 12 Localities — Meijer (1959) described four sections metres in the Albert Canal sections. Van der Ham in the and der Ham al. exposing early Palaeocene (Danian) strata (1988) van et (1987) discussed the of the Maastrichtian while & of this difference in thickness with ref- type area Stage, Jagt implications 74 the distinctive echinoid faunas result the that erence to highly from fact more samples from the the recently collected from uppermost part of the latter locality were studied. Geulhem Member along the Albert Canal. During 1985 and 1986 there were ample opportunities for Number of Albert Canal Geulhem extensive collecting, but, unfortunately, the various specimens small could be outcrops not combined to a standard > 200 extremely frequent extremely frequent section. if Most, not all, outcrops are no longer 101-200 very frequent extremely frequent accessible. 51-100 frequent very frequent Most studied herein come from the samples 21-50 common frequent Albert Canal those of 11-20 sections, e.g. Meijer (1959), not rare common 6-10 now incorporated into the collections of the Geolo- rare not rare 3-5 very rare rare gisch-Palaontologisches Institut und Museum der 2 extremely rare very rare Universitat in addition to and Hamburg, samples 1 extremely rare extremely rare specimens collected by E. Voigt, J.W.M. Jagt and M. Jager. Only few of the samples studied were collected from the Geulhem section by M. Meijer SYSTEMATIC DESCRIPTIONS and E. Voigt. Stratigraphy — Meijer (1959) subdivided the sections Family Serpulidae Rafinesque, 1815 exposed at Geulhem and along the Albert Canal Subfamily Filograninae Rioja, 1923 lower unit Genus 1956 into two units, a comprising more Cycloserpula Parsch, (= coarsely-grained, glauconitic biocalcarenite with Glomerula Regenhardt, 1961 sensu spines of the echinoid Tylocidaris hardouini (Desor, Briinnich Nielsen, 1931; Omasaria 1855) and few specimens of the inarticulate bra- Regenhardt, 1961) chiopod Danocrania geulhemensis (Kruytzer & Meijer, and unit of less — Goldfuss, 1831. 1958), an upper consisting coarse- Type species Serpula flaccida — sediment with of the Remarks A more detailed grained many specimens cra- study (in comparison with of niid brachiopod and few spines of the echinoid T. Jager, 1983) Jurassic and early Cretaceous has shown doubt that bruennichi Ravn, 1928. The reader is referred to Jagt serpulids, beyond the late & Collins and is (1988) Jagt & Janssen (1988) for a Bajocian (Dogger) species, flaccida Goldfuss, 1831 and more detailed discussion. congeneric, very probably even conspecific — 1820. Correlation with the type Danian Tylocidaris bruennichi with, gordialis von Schlotheim, Parsch (1956) of is an important key index fossil for the middle Dan- designated flaccida type species Serpula (Cycloser- ian in above while of Denmark; as mentioned this species pula), gordialis was designated type species in the unit of the Geulhem A Glomerula Briinnich occurs upper Member. by Regenhardt (1961). of this member with the Nielsen had the precise correlation type (1931) previously suggested name Glomerula Danian succession is currently impossible (see dis- but had failed to designate a type species, cussion injagt & Collins, 1988). which is why Regenhardt's designation is valid. — Glomerula is of Synonymies The taxa, Cycloserpula lombricus, Consequently, a junior synonym Cycloserpula. In of the fact that Glomerula was Pyrgopolon (Pyrgopolon) mosae mosae, P. (P.) m. ciplyana spite well also and defined Briinnich Nielsen, and that the com- and Bipygmaeus pygmaeus occur are com- by with in the late Cretaceous bination the name renders a clear moner underlying strata. specific pic- of the characteristic of the These species and subspecies will be described in ture shape tube, Cycloser- was used artificial omnium for detail(Jager, in prep.) in the Illustrated Catalogue of late pula as an gatherum all kinds of circular tubes distinct Cretaceous fossils from Limburg (The Netherlands) and lacking longitudi- To nal adjacent areas (J.W.M. Jagt, editor). avoid repeti- sculpture. here and — tion, synonymies are kept to a minimum, Diagnosis Tube solitary, or a number of inter- is made contributions in and tubes In reference to now press twined forming clusters. clusters, tubes nor- in preparation. mally not parallel to each other; only occasionally — Below is tabulated the of the bundles be less Frequency frequency may more or parallel. various in the sections studied. Differen- Tube in species two very long, very slowly increasing diame- curved with anterior tube ces between the Geulhem and Albert Canal sections ter, strongly, parts mostly 75 for- the does in central growing thigmotaxically along posterior parts, not, genus not appear Europe three- before the mid-Late Toarcian. It is absent ming two-dimensional meanders, two- or probably and dimensional charac- from the bifrons Zone of Somerset (England), irregular spirals or, highly from the mid-Late Toarcian teristically, three-dimensional chaotic knots. Very with certainty jurense in the limestone nodule in SW Ger- often the substrate is a foreign body only layer (sensu stricto) tube the At another late Toarcian nodule level, posterior part, whereas in the anterior part many. only older tube used substrate. At the of one foot above the level, sud- parts are as start jurense Cycloserpula and it remains of tube growth and between the strongly curved tube denly becomes fairly common one with there be curved the commonest until Danian time, a parts may straight or only slightly serpulids Bathonian. which not become erect decline the segments, may or may slight during of i.e. tube above the substrate. The dominance straight, non-coiled, ' life in results from the common Breakage of tube during frequently occurs: a parts ;'flaccida probably mollus- tube then from the of the occurrence and comparatively large size of new part grows cavity first shells in the late