Bernd-D. Erdtmann

Occurrence of Byronia Matthew and Sphenothallus Hall in the Lower Cambrian of China

KurzfassungSeltene phosphatische röhrchenförmige Fossilien aus der unter- bis mittelkambrischen Kaili- Formation aus der Provinz Guizhou (Kiautschau) in Südchina wurden als nicht-calcifizierte Algen oder als, Würmer’ (ScoleciellusLiu) identifiziert. Eine erneute Untersuchung dieser Fossilien erwies, daß die Fundstücke, die als nicht-verkalkte Algen bestimmt wurden, zuSphenothallus taijiangensis n. sp. zu stellen sind, während jene Exemplare, die alsScoleciellus identifiziert wurden, zuByronia natus (Liu) gehören.Sphenothallus taijiangensis undByronia natus aus den unterkambrischen Schichten der Kaili-Formation sind die ältesten Vertreter dieser Gattungen.Byronia natus ist, nebenB. AnnulataMatthew (Mittelkambrium von Britisch Kolumbien), die einzige bekannte Art dieser Gattung. CambrovitusMao et al., ein röhrchenförmiges Fossil aus den mittelkambrischen Schichten der Kaili-Formation, wurde ursprünglich zu den Hyolithiden gestellt. Die Entdeckung eines nahezu vollständigen Exemplars mit einer apikalen Haftscheibe deutet darauf hin, daßCambrovitus, ähnlich wieByronia undSphenothallus, wahrscheinlich ein thekentragender cnidarer Polyp war.AbstractRare phosphatic tubular fossils from the Lower-Middle Cambrian Kaili Formation of Guizhou Province, southern China were originally identified as non-calcified algae or ‘worms’ (ScoleciellusLiu). Re-examination of these fossils indicates that specimens identified as non-calcified algae areSphenothallus taijiangensis n. sp., while specimens identified asScoleciellus belong toByronia natus (Liu).Sphenothallus taijiangensis andByronia natus from Lower Cambrian strata in the Kaili Formation are the oldest known representatives of their genera. In addition,B. natus (Liu) is the only known species ofByronia with the exception ofB. annulataMatthew (Middle Cambrian, British Columbia).CambrovitusMao et al., a tubular fossil from Middle Cambrian strata in the Kaili Formation, originally was classified as a hyolithid. However, the discovery of a nearly complete specimen possessing an apical attachment disk shows thatCambrovitus, likeByronia andSphenothallus, probably was a thecate cnidarian polyp.

The new Early Ordovician (Hunneberg Stage) graptolite genusParadelograptus (Kinnegraptidae), its phylogeny and biostratigraphy

KurzfassungNeuere Geländeuntersuchungen in der Sierra Morena (SW Spanien), am Hunneberg, Vastergötland (Schweden), und in gleichaltrigen unterordovizischen Schichten der Cow Head Gruppe (W. Neufundland, Kanada) sowie in der Lancefield-Bendigo Stufe (La2-Bel) von Victoria (Australien) erbrachten eine reiche Fauna zum Teil sehr feingliedriger, vielästiger, biradiater Graptoloiden (ohne Bitheken) mit »goniograptiden« bis »kinnegraptiden« Theken und einer ungeordneten Verteilung von Dichotomien. Diese Formen werden hier in einer neuen GattungParadelograptus n. gen. zusammengefaßt. Diese Gattung wird aufgrund ihrer spezifischen Thekenmorphologie und des »adelograptiden« Verzweigungsmodus als Übergangstaxon zwischen der dendroiden (bitheken-führenden) Unterfamilie Adelograptinae Mu 1974 und der graptoloiden Familie Kinnegraptidae Mu 1974 eingegliedert, zu denen diese neue Gattung gestellt wird. Folgende neue sowie bisher bekannte Arten werdenParadelograptus zugeordnet:P. onubensis n. sp. (Typusart),P. mosseboensis n. sp.,P. kinnegraptoides n. sp.,P. antiquus (Hall 1899),P. pritcbardi (Hall 1899),P. smithi (Harris & Thomas 1938a),P. ramulosus (Harris & Thomas 1938a),P. sedecimus (Harris & Thomas 1938a)P. rarus (Harris & Thomas 1938a) sowieP. problematicus (= »Clonograptustenellus var. problematica« Harris & Thomas 1938a). Weiterhin ist eine nane Verwandt-schaft für die folgenden Formen zu vermuten: »Clonograptustenellus sensu lato« Cooper & Stewart 1979, »Tetragraptus«chapmani Keble & Harris 1934, »Tetragraptus«clarkefieldi Thomas & Keble in Harris & Thomas 1938b und für »Tetragraptus«bulmani Thomas 1973. Morphogenetische Verbindungen zwischenParadelograptus und der dichograptiden (?) GattungTrichograptus Nicholson 1876, der sigmagraptiniden GattungenLaxograptus Cooper & Fortey 1982 undEtagraptus Ruedemann 1904 sowie den bisher bekannten kinnegraptiden GattungenKinnegraptus Skoglund 1961,Prokinnegraptus Mu 1974 undWuninograptus Ni 1981 werden ebenfalls vermutet. Entwicklungsgeschichtlich überlieferte anisograptide Merkmale wie die »isograptide« Proximalentwicklung und die unregelmäßige Anordnung der dikalykalen Theken bis hin zu den mittel-bis oberarenigischen Vertretern der Kinnegraptidae und Sigmagraptinae werden offensichtlich beibehalten, wohingegen Merkmale wie der Verlust der Bitheken und die Auslängung der prothekalen Bereiche (goniograptides Merkmal), die Ausbildung von Mün-dungsfortsätzen der Sikula und der Theken sowie die Peridermverdünnung (kinnegraptide Merkmale) bereits bei einigenParadelograptus- Arten sich im evolutiven Entwicklungsverlauf befinden bzw. vorgebildet sind.Stratigraphisch gesehen sind dieParadelograptus-Arten charakteristisch für die weltweite transgressive Hunneberg-Stufe von Tjernvik (1956), die mit dem La2 bis Bel in Australien und Neuseeland zu korrelieren ist. In den Typusgebieten der Tremadoc- und Arenig-Stufen in Nordwales ist dieser geologische Abschnitt ablagerungsmäßig nicht repräsentiert bzw. enthält eine Diskordanz, die diesem Intervall entsprechen würde.AbstractRecent field investigations in the Sierra Morena (SW Spain), at the Hunneberg Mountain, Västergötland (Sweden) and in corresponding strata of the Cow Head Group (W. Newfoundland, Canada) as well as in the Lancefieldian (La2 to Bel) black shale bands of Victoria (Australia) have produced, inter alia, a diverse fauna of very delicate multibranched biradiate graptoloids (without bithecae), which possess “goniograptid” to “kinnegraptid” thecae and an adventitious number and arrangement of dichotomies (ranging from none to 6th and higher orders), reminiscent of the dendroid Adelograptinae Mu 1974. These characteristic forms are here assembled in the new genusParadelograptus, a genus which by virtue of its specific thecal morphology and its “adelograptoid” branching pattern is regarded as intermediate between the dendroid Adelograptinae Mu 1974 and the graptoloid family Kinnegraptidae Mu, 1974, into which this genus is here included. The following species are assigned toParadelograptus: P. onubensis n. sp. (type species),P. antiquus (Hall 1899),P. pritchardi (Hall 1899),P. smithi (Harris & Thomas 1938a),P. ramulosus (Harris & Thomas 1938a),P. sedecimus (Harris & Thomas (1938a),P. rarus (Harris & Thomas 1938a),P. problematicus (- “Clonograptus tenellus var. problematica”) Harris & Thomas 1938a,P. mosseboensis n. sp., andP. kinnegraptoides n. sp. A close relation toParadelograptus is also presumed for “Clonograptustenellus sensu lato” Cooper & Stewart 1979, “Tetragraptus”chapmani Keble & Harris 1934, “Tetragraptus”bulmani Thomas 1973, and “Tetragraptus”clarkefieldi Thomas & Keble in Harris & Thomas 1938b. Morphogenetic relations betweenParadelograptus and the dichograptinid (?) genusTrichograptus Nicholson 1876, the sigmagraptinid generaLaxograptus Cooper & Fortey 1982 andEtagraptus Ruedemann, 1904 as well as to the previously established kinnegraptid generaKinnegraptus Skoglund 1961,Prokinnegraptus Mu 1974, andWuninograptus Ni 1981 are also postulated. PhylogeneticallyParadelograptus demonstrates that conservative anisograptoid features, such as the isograptid proximal branching mode and the adventitious positions of dicalycal thecae are retained and transferred both to the middle-late Arenig Kinnegraptidae and to the Sigmagraptinae, whereas the loss of bithecae, elongation of prothecal “tubes” (a goniograptid character) and formation of thecal apertural “lappets” as well as thecal periderm attenuation (kinnegraptid characters) are already introduced in stratigraphically early species belonging toParadelograptus.Stratigraphically all species are characteristic of the globally transgressive Hunneberg Stage of Tjernvik, 1956 which corresponds to the interval La2 to Bel of the Australasian stages or to the interval not represented by strata of Tremadoc or Arenig age in their areas in Great Britain, where a hiatus separates these series.

Lower Cambrian small shelly faunas from Zhejiang (China) and their biostratigraphical implications

Abstract Despite a long history of research on the Early Cambrian in China most available data on small skeletal fossils concern fossil associations of the shallow carbonate platform. Information on skeletal fossils from marginal shelf environments of the Yangtze Platform is scanty, which may reflect the rarity of fossils in deeper sedimentary environments but is also due to limitation of carbonate distribution and outcrops, difficulties in fossil extraction, and a general research focus on the Precambrian—Cambrian boundary beds on the carbonate platform. Here we present a documentation of Meishucunian to Qiongzhusian smallskeletal fossils from the lower Hetang Formation and the chert unit at its base from the Jiangshan region, Zhejiang Province, representing a relatively deep shelf environment compared to the inner shelfregion. The earliest association (Meishucunian) from the chert unit underlying the Hetang Formation is mainly characterized by the occurrence of Protohertzina anabarica, P. unguliformis, ...

Early Cambrian protoconodonts and conodont-like fossils from China: Taxonomic revisions and stratigraphic implications

Abstract Protoconodonts and conodont-like microfossils are characteristic components in the early Cambrian skeletal faunas. Sincethe 1970s, these tooth-like phosphatic sclerite fossils have been widely recovered from the Lower Cambrian of China, and altogether 25 genera and 52 species of protoconodonts and conodont-like fossils have been described, although some taxa represent synonyms or invalid taxonomic names, and some assignments are apparently inappropriate. Through a brief review and discussion, the distinction between protoconodonts and conodont-like fossils is denoted here. Thereare 13 genera previously assigned to protoconodonts in the literature, but present taxonomic revisions show that 5 of them are junior synonyms of other taxa, and 2 represent unknown arthropods. The other 12 genera, of which 5 also are junior synonyms, only reveal a conodont-like morphology with various zoological affinities: most of them are enigmatic, and only Beshtashella and Parafomitchella (=Beshtashella) can be assign...

Tremadocian (early ordovician) graptolite biostratigraphy of China

Based on a study of latest Tremadocian graptolites from Gulin of southern Sichuan and a re-examination of Tremadocian graptolite specimens previously collected from many other localities in South China, a new scheme of Tremadocian graptolite biozonation is proposed for the South China palaeoplate, to include seven zones. The discovery of Hunnegraptus novus and H. sp. from the top part of the Tungtzu Formation in Gulin indicates an age of latest Tremadocian (Hunnegraptus copiosus Zone). The Tremadocian graptolite succession of North China is also discussed and the Aorograptus victoriae Zone is suggested as a replacement of the former, misinterpreted, Adelograptus-Clonograptus Zone. A correlation of the revised graptolite biozonation of South China and North China with those of other continents is proposed. Zusammenfassung. Auf der Grundlage einer Neubearbeitung der jungsten Tremadocium-Graptolithen, die von vielen verschiedenen Lokalitaten Chinas stammen, wird eine neue Biozonierung der Graptolithen-Abfolge in sieben Zonen fur die Tremadocium-Stufe der sudchinesischen Platte vorgeschlagen. Die Entdeckung von Hunnegraptus novus und H. sp. aus den hochsten Schichten der Tungtzu Formation in Gulin (Provinz Sichuan) weist auf ein jungstes Tremadocium-Alter (Hunnegraptus copiosus Zone) hin. Die Tremadocium-Graptolithenabfolge von Nordchina wird ebenfalls besprochen und die dort nachgewiesene Aorograptus victoriae Zone als Ersatz fur die vormals misgedeutete Adelograptus-Clonograptus Zone empfohlen. Eine Korrelation der revidierten Graptolithen – Biozonierung von Sudund Nord-China mit der Zonierung anderer Kontinente wird vorgeschlagen.

Malongitubus: a possible pterobranch hemichordate from the early Cambrian of South China

Abstract. Malongitubus kuangshanensis Hu, 2005 from the early Cambrian Chengjiang Lagerstätte of China is redescribed as a pterobranch and provides the best evidence to demonstrate that hemichordates were present as early as Cambrian Stage 3. Interpretation of this taxon as a hemichordate is based on the morphology of the branched colony and the presence of resistant inner threads consistent with the remains of an internal stolon system. The presence of fusellar rings in the colonial tubes cannot be unambiguously proven for Malongitubus, probably due to early decay and later diagenetic replacement of the thin organic material of the tubarium, although weak annulations are still discernible in parts of the tubes. The description of M. kuangshanensis is revised according to new observations of previously reported specimens and recently collected additional new material. Malongitubus appears similar in most features to Dalyia racemata Walcott, 1919 from the Cambrian Stage 5 Burgess Shale, but can be distinguished by the existence of disc-like thickenings at the bases of tubarium branching points in the latter species. Both species occur in rare mass-occurrence layers with preserved fragmentary individuals of different decay stages, with stolon remains preserved as the most durable structures. Benthic pterobranchs may have occurred in some early Cambrian shallow marine communities in dense accumulations and provided firm substrates and shelter for other benthic metazoans as secondary tierers.

Astogenetic aspects of the dendroid graptolite Airograptus (Late Cambrian‐Early Ordovician) and their phylogenetic implications

Based on a Backscatter Electron (BSE) examination of partially 3-dimensional graptolite specimens of Airograptus from the Tremadocian (Early Ordovician) Yehli Formation at Dayangcha, Baishan of Jilin Province, NE China, the thecal structure and astogenetic aspects of this genus (except for the missing proximal part) are described and illustrated in detail. In the present collection, no furcating but only peltate thecal apertural processes are confirmed. A comparison between the presumably benthic dendroid Airograptus and Rhabdinopora, the earliest planktonic graptolite, indicates that there are remarkable similarities in astogenetic aspects between them, although there are also differences in the development of dissepiments and thecal apertural processes. A possible ancestor-descendent relationship between the two genera is herein proposed.