Germany) and Its Bearing on the Tectonostratigraphic History of the Saxothuringian Domain

Pala¨ontol Z (2014) 88:239–262 DOI 10.1007/s12542-013-0195-z

RESEARCH PAPER

A new lowermost middle Cambrian (Series 3, Stage 5) faunule from Saxony (Germany) and its bearing on the tectonostratigraphic history of the Saxothuringian domain

Gerd Geyer • Bernd Buschmann • Olaf Elicki

Received: 11 February 2013 / Accepted: 18 July 2013 / Published online: 10 August 2013 Ó Springer-Verlag Berlin Heidelberg 2013

Abstract The core of borehole 1209/78 west of Dober- Middle Cambrian fauna known from the Saxothuringian lug–Kirchhain and south of Herzberg in the Torgau– domain and reconfirm the palaeogeographic position in the Doberlug Syncline records an atypical lower part of the Perigondwanan segment. The lithological differences of the Tro¨bitz Formation with thin limestone horizons. These fossiliferous cores from those of the typical Tro¨bitz For- limestone layers include the remains of a low to moderately mation and the recorded high-energy conditions indicate diverse fauna with the trilobites Protolenus (Hupeolenus) high-frequency sea-level changes suggesting that this part bergstroemi n. sp., Cambrunicornia saxonica n. sp., of the succession may be a late stage of the subglobally Ornamentaspis? aff. todraensis Geyer 1990a, Calodiscus? recognizable eustatic sea-level fluctuations at the traditional n. sp., the remains of two undetermined olenelloid? and Lower–Middle Cambrian boundary interval. paradoxidid? species, at least two brachiopods (Tremato- bolus, undetermined acrotretoid), and one hyolith. The Keywords Cambrian Á Trilobita Á Brachiopoda Á fauna clearly suggests a position in the lower Agdzian stage Biostratigraphy Á Sea-level fluctuations Á of the West Gondwana chronostratigraphic scheme and Saxo-Thuringian Zone Á Germany correlation with the lowermost to lower Middle Cambrian strata in regions such as the Moroccan Atlas ranges and Kurzfassung Bohrkerne der westlich von Doberlug–Kir- northern Spain, so the assemblages represent the oldest chhain und su¨dlich von Herzberg in der Torgau–Doberlug– Synkline niedergebrachten Bohrung 1209/78 zeigen einen atypisch ausgebildeten unteren Teil der Tro¨bitz-Formation & G. Geyer ( ) mit du¨nnen Kalkstein-Horizonten. Diese Kalkstein-Lagen Institut fu¨r Geographie und Geologie, Lehrstuhl fu¨r Geodynamik und Geomaterialforschung, Bayerische Julius-Maximilians- beinhalten eine gering bis mittelstark diverse Fauna mit den Universita¨tWu¨rzburg, Am Hubland, 97074 Wu¨rzburg, Germany Trilobiten Protolenus (Hupeolenus) bergstroemi n. sp., e-mail: [email protected] Cambrunicornia saxonica n. sp., Ornamentaspis? aff. todraensis Geyer 1990, Calodiscus? n. sp., Resten von zwei G. Geyer Department of Earth Sciences (Palaeobiology), unbestimmbaren Arten vermutlich olenelloider und para- Uppsala University, Villava¨gen 16, doxidider Trilobiten, mindestens zwei Brachiopoden (Tre- 752 36 Uppsala, Sweden matobolus, ein nicht pra¨zise bestimmbarer Acrotretide) sowie einem Hyolithen-Operculum. Die Fauna belegt eine B. Buschmann Á O. Elicki Institut fu¨r Geologie, TU Bergakademie Freiberg, stratigraphische Position im unteren Agdzium der fu¨r West- Bernhard-von-Cotta-Straße 2, 09599 Freiberg, Germany Gondwana gu¨ltigen chronostratigraphischen Gliederung e-mail: [email protected] und korreliert mit Schichten des untersten bis unteren Mit- O. Elicki telkambrium in Regionen wie den marokkanischen Atlas- e-mail: [email protected] Ketten und Nord-Spanien. Damit repra¨sentieren die Verge- sellschaftungen die a¨ltesten mittelkambrischen Faunen, die B. Buschmann Erz & Stein GbR, Hof am Alten Fernweg, Talstraße 29, aus dem Saxothuringikum bekannt geworden sind. 09627 Bobritzsch, Germany Sie besta¨tigen ebenso die palaögeographische Position 123 240 G. Geyer et al. im Perigondwana-Segment. Die lithologischen Unterschiede relatively narrow stratigraphic interval of mid Middle der fossilfu¨hrenden Schichten zur typischen Ausbildung der Cambrian age (early Caesaraugustan) (Geyer et al. 2008; Tro¨bitz-Formation und die dokumentierten hochenergetis- Elicki and Geyer 2010). chen Ablagerungsbedingungen lassen hochfrequente Meer- Unfortunately, the transition from Lower to Middle esspiegelschwankungen in diesem Teil des Profils vermuten Cambrian strata is unknown. This led to the assumption und scheinen eine spa¨te Phase der subglobal nachweisbaren that a significant stratigraphic gap between the strata of the eustatischen Meeresspiegelschwankungen im traditionellen two series is present in this area, which leaves space for the U¨ bergangsbereich Unter-/Mittelkambrium abzubilden. assumption of a major hiatus synchronized with subglobally recognizable eustatic sea-level fall commonly sum- Schlu¨sselwo¨rter Kambrium Á Trilobita Á marized as the ‘‘Hawke Bay regression’’ (Palmer and Brachiopoda Á Biostratigraphie Á James 1980). The supposition of a major break in deposi- Meeresspiegelschwankungen Á Saxothuringikum Á tion starting well within the Early Cambrian would have Deutschland suggested a late transgression so that part of the lower Middle Cambrian would not be recorded by strata. How- ever, a newly identified faunal assemblage from the Tro¨bitz Introduction Formation in a drill core from west of Doberlug–Kirchhain and south of Herzberg (drill core 1209/78; Fig. 1), briefly Fossiliferous Cambrian rocks are rare in Central Europe reported in 2006 (Geyer and Buschmann 2006) and but fairly well preserved in Lusatia and northern Saxony, described in detail below, reduces this supposed hiatus Germany. Although the mode of preservation is quite dif- considerably. This fauna represents the lowermost Middle ferent between the two regions, the lithologies suggest a Cambrian lower Agdzian as recorded in areas with a nearly common depositional domain that also indicates a common complete record of the Lower–Middle Cambrian boundary faunal province with distinct signatures of the West Gon- interval (for example northern Spain and southern Mor- dwanan faunal realm. The Cambrian subsurface rocks of occo). Consequently, the presently recognized gap may the Delitzsch–Torgau–Doberlug Synclinorium in northern indeed be created by incomplete biostratigraphic data Saxony and adjacent areas do not represent a continuous rather than physical absence of strata. succession, because of subsequent tectonic displacement. Deposition during the Cambrian sedimentation starts after a stratigraphic and structural gap (Cadomian unconformity) with local conglomeratic debris flow deposits, followed by the Lower Cambrian composed mainly of shallow marine carbonates and minor siliciclastics with common calcimicrobial biogenic carbonates. The Middle Cambrian generally comprises siliciclastics with scarce carbonate intercalations. The Tro¨bitz Formation, dominated by quartzitic sandstones and alternating with micaceous claystones is early but not earliest Middle Cambrian (Cambrian Series 3 and Stage 5) in age as indicated by comparatively rich fossil assemblages with trilobites, inarticulate brachiopods, and hyoliths (Schmidt 1944; Sdzuy 1957a, b, 1970). The trilobites indicate a stratigraphic level corresponding to the middle to upper Agdzian sensu Geyer and Landing (2004) (=Leonian in the Iberian regional scheme; Sdzuy et al. 1999). The overlying Deli- tzsch Formation consists of quartzarenitic sandstones alternating with claystones. As in the Tro¨bitz Formation, Fig. 1 Distribution of Hercynian Massifs and selected structural units the faunas are dominated by trilobites, inarticulate bra- in present-day central and western Europe (modified from Franke chiopods, and hyoliths. Two different stratigraphic levels 1989 and Buschmann et al. 2006). Abbreviations of structural units: can be distinguished. The older level has an early Middle AF Alpine front, AM Armorican Massif, BM Bohemian Massif, Cambrian age equivalent to the younger fauna of the MGCH mid-German Crystalline High, RH Rheno-Hercynian Zone, ST Saxo-Thuringian Zone, TB Tepla´–Barrandian Zone, TDS Torgau– Tro¨bitz Formation. A younger fauna with trilobites, bra- Doberlug Syncline, TESZ Teiseyre-Tornquist Line forming the chiopods, and helcionelloid molluscs characterizes a northern border of the Trans-European Suture Zone

123 A new lowermost middle Cambrian 241

Geology and Cambrian stratigraphy Cambrian formations known thus far can be interpreted of the Delitzsch–Torgau–Doberlug Synclinorium either as because of a gap in the drilled rocks or as a true hiatus because the studied core profiles provided either The Delitzsch–Torgau–Doberlug Synclinorium consists of exclusively Lower Cambrian or Middle Cambrian strata. two synclines, known as the Torgau–Doberlug Syncline Some authors suggested ‘‘Sardic’’ tectonic deformation (TDS) and the Delitzsch Syncline (Figs. 1, 2). The TDS is (Brause 1969); this can be rejected on the basis of current a subsurface structural unit of Ediacaran and Palaeozoic information. Apparent gaps between the Middle Cambrian rocks in the Saxo-Thuringian Zone covered by up to 200 m units are most likely to be because of the contemporary of Cenozoic strata. The pre-Cenozoic rocks have been exposure situation. The total thickness of Cambrian strata explored by use of drill holes reaching depths of up to in the TDS is estimated at up to 1,500? m. 1,200 m. This pre-Cenozoic succession comprises Ediac- Deposition during the Cambrian started after a strati- aran, Lower and Middle Cambrian strata. In central parts of graphic and structural gap termed the Cadomian uncon- the TDS Viseán rocks are present (Buschmann et al. 1995, formity (Buschmann et al. 2006; Linnemann et al. 2008). 2006). They overlie the Cambrian strata with angular The succession commences with local conglomeratic deb- unconformity (Brause 1969;No¨ldeke 1976). ris flow deposits, followed by Lower Cambrian represented The very low-grade Ediacaran rocks in the TDS are by shallow marine carbonates and minor siliciclastics with more intensely folded and cleaved than the Cambrian common calcimicrobial biogenic carbonates that contain strata, which do not record a notable regional metamorphic archaeocyaths (Freyer and Suhr 1987, 1992; Elicki and overprint (Buschmann 1995). In Central Europe, a com- Debrenne 1993; Elicki 1999), which seem to indicate an parable succession is known only from core sections Issendalenian age sensu Geyer and Landing (2004). Bila- around a Variscan plutonite complex in the small Delitzsch terian skeletal fossils are rare and do not indicate a precise Syncline approximately 40 km to the west (Elicki 1992; stratigraphic position of the strata (Elicki 1994; Elicki and Buschmann 1995). Relationships between the Ediacaran of Wotte 2003). The endemic trilobite Dolerolichia pretiosa the TDS and the adjoining tectonostratigraphic units to the Sdzuy 1962 is best regarded as a late Early Cambrian (early south are unclear because contacts between the structural Banian) fossil (Elicki and Geyer 2010). units are buried. The Middle Cambrian consists of units summarized as The Cambrian strata of the Torgau–Doberlug Syncline the Arenzhain Group (composed of the Tro¨bitz and Deli- are lithostratigraphically subdivided into the Lower Cam- tzsch formations) and is represented by siliciclastics with brian Zwethau Formation and the Middle Cambrian Tro¨- minor carbonate intercalations (Brause 1969, 1970; Elicki bitz and Delitzsch formations (Fig. 3) (Freyer and Suhr 1997). The Tro¨bitz Formation is dominated by quartzitic 1987; Brause and Elicki 1997; Elicki 1999). The sub- sandstones alternating with micaceous claystones. stantial stratigraphic gap between the Lower and Middle Comparatively rich fossil associations with trilobites,

Fig. 2 Geological sketch map of the Torgau–Doberlug Syncline with distribution of rock complexes at the pre- Cenozoic surface (according to geophysical mapping and results from drill cores) plus location of drill hole 1209/78, LS 1/63, and the adjacent old drillings ‘‘Dobrilugk’’ and D I. Values indicate UTM coordinates. Modiﬁed from Buschmann et al. (2006, Fig. 2)

123 242 G. Geyer et al.

(Sdzuy 1970), and Parasolenopleura lusatica Sdzuy 1970, the brachiopod ‘‘Lingulella’’ sp., and the hyoliths ‘‘Tulen- icornis’’ cf. oelandicus (Holm 1893), Decoritheca? aff. affinis (Holm 1893), and ‘‘Orthotheca’’ sp. indet. (nomenclature partly emended herein). From a second stratigraphic level between the depths of 486.8 m and 385.6 m, Sdzuy (1970) described assemblages with the trilobites Acadoparadoxides cf. insularis (Westerga˚rd 1936), Paradoxides? aff. enormis Sdzuy 1968, and Kin- gaspidoides? incultus (Sdzuy 1970), the brachiopod ‘‘Lin- gulella’’ sp., and the hyoliths ‘‘Tulenicornis’’ cf. oelandicus (Holm 1893) and Decoritheca? aff. affinis (Holm 1893). The faunas from the drill cores described by Schmidt (1944) are much more diverse. However, the assemblages are difficult to characterize because of lack of precise information about some depth intervals. Nevertheless, it should be emphasized that the trilobites of the oldest assemblage include Kingaspidoides annulatus (Schmidt 1944) (not 1942 as commonly cited!) which seems to be most closely related to Kingaspidoides frankenwaldensis (Wurm 1925) from the Galgenberg Formation of the Franconian Forest (Frankenwald) area in northern Bavaria. The faunas of the Galgenberg Formation, however, can be correlated with sufficient precision with the Morocconus notabilis Zone of the Atlas ranges in Morocco, which are early Agdzian in age. This zone (earlier termed the Fig. 3 Cambrian stratigraphy in the Torgau–Doberlug Syncline. The Lower Cambrian succession is based on numerous core profiles Cephalopyge notabilis Zone and renamed because of the whereas the Middle Cambrian column is drawn from reference junior homonyme of its eponymous index species, marks a profiles (boreholes D I, LS 1/63, D IV). Gaps not to scale. Modified generally amply fossiliferous interval which is well rec- from Elicki (2007, Fig. 3) ognisable in West Gondwana and other regions (Geyer and Peel 2011, Elicki and Geyer 2013). inarticulate brachiopods, and hyoliths indicate early, but The overlying Delitzsch Formation consists of domi- not earliest, Middle Cambrian age. The trilobites indicate a nating quartzarenitic sandstones alternating with clay- stratigraphic level equivalent to the Iberian Eccaparadox- stones. As in the Tro¨bitz Formation, the faunas are ides sdzuyi biozone, corresponding to the middle to upper dominated by trilobites, inarticulate brachiopods, and Agdzian and Celtiberian sensu Geyer and Landing (2004), hyoliths. Two different stratigraphic levels can be distin- i.e. Cambrian Series 3 and Stage 5 (=middle Leonian in the guished. The older level has an early Middle Cambrian age, Iberian regional scheme; Sdzuy et al. 1999). Fossils from equivalent to the younger faunal assemblage of the Tro¨bitz the drill cores were first studied by Schmidt (1944) (drill Formation. It is represented by the youngest assemblages in cores ‘‘Dobrilugk’’, D I and D IV; Fig. 2). This material drill core LS 1/63 (mentioned above) between the depths of and the material from the drill cores of the 1950s and 1960s 241.4 and 197.9 m and includes the richest fauna from were studied in detail by Sdzuy (1957a, b, 1958, 1970, which Sdzuy (1970) described the trilobites Condylopyge 1972). The oldest well-documented Middle Cambrian cf. regia (Sjo¨gren 1872), Peronopsis sp., Acadoparadox- assemblages are known from drill core LS 1/63 (close to ides brausei (Sdzuy 1970), Acadoparadoxides sp. indet., Doberlug–Kirchhain Fig. 2) (Brause 1970). The oldest Parasolenopleura lusatica Sdzuy 1970, and Bailiella cf. remains in this drill core were only very large fragments of emarginata (Linnarsson 1877), the hyoliths ‘‘Tulenicornis’’ thoracic segments of Paradoxides sensu lato, which Sdzuy cf. oelandicus (Holm 1893) and ‘‘Orthotheca’’ sp. indet., (1970) determined as ‘‘Paradoxides’’? aff. enormis Sdzuy and the problematic fossil Oxyprymna schloppensis (Wurm 1968, because tentatively determinable large sclerites were 1925) (nomenclature partly emended here). The material discovered in younger levels of the core. Fairly well doc- originally described as Condylopyge cf. regia has at least umented assemblages were discovered in the core between partly been assigned to Condylopyge cruzensis Linãn and the depths of 848.4 and 756.7 m. They yielded the trilo- Gozalo 1986 by Sdzuy et al. (1999) and Dies & Gozalo bites Acadoparadoxides? sp., Kingaspidoides? incultus (2004). All assemblages from the LS 1/63 drill core 123 A new lowermost middle Cambrian 243 indicate that—despite the enormous thicknesses suggested calcite input or even mild dolomitization in accordance by the distances between the sample levels—the strati- with an anchimetamorphic overprint. graphic differences are relatively minor and all faunas The general lithology of this part of the core indicates a belong to the lower part of the Middle Cambrian. It should facies that differs to some extent from that of the typical be noted that Sdzuy (1970) described two new species of Tro¨bitz Formation. Consequently, it may be interpreted as Acadoparadoxides from the drill cores, Acadoparadoxides a lithostratigraphic unit in stratigraphical contact with the brausei (Sdzuy 1970) and A. saxonicus (Sdzuy 1970) (from Tro¨bitz Formation with its slightly younger which has not drill core De 8/63 near Grebehna), both of which were yet been identified from other parts of the Torgau–Dober- based on material without pygidia so that the most char- lug Syncline. However, the original definition of the Tro¨- acteristic features are unknown. bitz Formation was based solely on data from one single A younger fauna in the Delitzsch Formation includes drill core (Brause 1970) so that the lithological variation of also trilobites, brachiopods, and helcionelloid molluscs. the formation is imperfectly known. As a result, interpre- Most trilobites in these assemblages, for example Badule- tation and identification of this unit from drill cores only sia tenera (Hartt in Dawson 1868), represent a relatively has led to increasing uncertainty with increasing distance narrow stratigraphic interval of mid Middle Cambrian age from the type locality. (early Caesaraugustan).

Preservation of the fossils Properties and characters of drill core 1209/78 The fossils from the studied horizons between ca. 300 and The holes drilled in the 1950s, 1960s, and 1970s were 345 m depth of the core include remains of three six tri- intended to serve as major information in the search for lobite and at least two brachiopod species. Despite the mineral resources in the German Democratic Republic. A relative paucity of the fauna, because of the limited number of drill cores from the TDS had never been studied amount of material from the core, the preservation is scientifically and had been deposited in a central reposi- remarkably good with only faint distortion of the speci- tory. Most material of the cores has been discarded for mens and partial shell preservation. The fossils are pre- economic reasons during reorganization in 1994, after served as fragments of disarticulated sclerites of very German reunification. Among the small amount of material different sizes and with sharp angular broken edges. They rescued for scientific research by staff of the TU Bergak- are not well sorted and sometimes of surprisingly different ademie Freiberg were small amounts of rocks from a core sizes and frequently embedded with the ventral face (drill core 1209/78), obtained in 1978, which penetrated upward or even oblique to the bedding plane so that the Middle Cambrian rocks west of Doberlug–Kirchhain and remains suggest rapid deposition under high-energy con- south of Herzberg (UTM coordinates r5719848 h4581980) ditions and limited transport. (Fig. 2). A few fossil shells are crushed, because of compaction. The Middle Cambrian rocks of this core are approxi- As noted above, the fossil shells are generally slightly mately 350 m thick up to the final depth of the core at the recrystallized. Nevertheless, the calcite of the shells is fine- depth of 477 m (Fig. 4). The material included thin lime- grained and almost never sparry and has fairly high mag- stone layers with small flakes of light coloured mica nesium content. Remarkably, the surfaces show details, but intercalated with thin-bedded alternations of mudstones, often the fine sculptures appear somewhat blurry. They siltstones, and sandstones with rapidly vacillating lithol- tend to break not exactly at the original external surface of ogy. Also noted are layered to nodular limestones with the fossil, so exact preservation has often been difficult and partly conspicuous amounts of shell fragments. These the specimens tend to appear slightly out of focus on some calcareous horizons occur between ca. 305–435 m of the of the photographs. core depth (Figs. 4, 5). They more or less postdate layers with black phosphorite and glauconite grains (between ca. 430 and 450 m). Systematic descriptions Determinable faunal remains occur in the thin light colored, mostly light grayish limestone beds (up to ca. The material from this study is housed in the palaeonto- 6 cm thick) with mica flakes between ca. 305 and 345 m logical collection of the TU Bergakademie Freiberg under depth. Layers with determinable fossil remains are listed in suite number FG 625 and the additional numbers provided Table 1. Mild to conspicuous recrystallization is observed below. The specimens have been blackened with graphite for single particles within the thin beds, and the preserva- suspension or diluted china ink before coating with mag- tion is generally indicative of a notably high magnesium nesium oxide or ammonium chloride. 123 244 G. Geyer et al.

Fig. 4 Generalized lithological column of the core of borehole 1209/78 with the fossiliferous limestone layers studied here shown in red. Core loss and core gain are summarized for intervals with similar lithologies from cored sections. The positions of the samples are consistent with the position within the cored section

Phylum Arthropoda Latreille 1829 furrows. Eyes, palpebral lobes, eye ridges and suture absent. Class Trilobita Walch 1771 Lateral border convex, of more-or-less equal breadth Order Agnostida Kobayashi 1935 throughout. Posterior border convex, triangular in outline, Superfamily Eodiscoidea Richter 1932 developing from minimum breadth at dorsal furrow to sub- stantial width near genal corner, probably developing into Family Calodiscidae Kobayashi 1943 lateral border with a distinct angle of ca. 110°. Lateral border Genus Calodiscus Howell 1935 furrow distinct, groove-like, moderately broad, less well defined from border. Posterior border furrow decreasing in Type species. Agnostus lobatus Hall 1847. breadth and depth from genal angle toward dorsal furrow. Calodiscus? n. sp. A Surface of exfoliated gena coarsely granulate, test on border apparently with minute granules. (Fig. 9.1, 5) Discussion. The single specimen has characters typical of Material. Single partial cranidium, under FG 625/146e. the species assigned to the genus Calodiscus, particularly Calodiscus schucherti (Matthew 1896) and C. ibericus Locality and horizon. Drill core 1209/78, west of Do- (Sdzuy 1962) (originally introduced as Calodiscus schuc- berlug–Kirchhain and south of Herzberg, horizon at depth herti ibericus Sdzuy 1962, from the Sierra Morena, southern of 309.3 m. Spain). Both share the apparently long glabella, the front of Description. Incomplete cranidium with a length/width which reaches to the anterior border furrow and thus without ratio of presumably ca. 0.7–0.75. Glabella presumably with a preglabellar field. However, the glabella in the specimen subparallel sides, its frontal lobe probably reaching the from the Herzberg core is slightly shorter than in the Iberian anterior border furrow. Dorsal furrow deeply incised, specimens. The similar C. agnostoides (Kobayashi1943) confluent with anterior border furrow. Gena subsemicir- from Laurentian eastern North America also has fine gran- cular in outline, strongly convex, greatest height exsagit- ules on the test, but has a slightly clavate glabella (with the tally midlength, transversely ca. one-third from dorsal resulting curved dorsal furrow) (Rasetti 1952). 123 A new lowermost middle Cambrian 245

Mountains under the name Calodiscus n. sp. A (Geyer 1988, p. 94ff., text Figs. 22–26). As for this specimen, pygidia are unknown from the material from the approximately coeval Moroccan Morocconus notabilis Zone so sufficient diagnosis could not be provided for the Moroc- can form, but we believe the current specimen belongs to the same species. The generic assignment has to remain tentative as long as a consequent taxonomic characterization of the generic concept is not established, as in the case of Calodiscus. The distinctly older, late early Cambrian species Calodiscus lobatus (Hall 1847), as the prime example and epitome of the genus (Lochman 1956; Ahlberg and Bergstro¨m 1993; Cederstro¨m et al. 2005, 2009), has a morphology which reflects a state in the ontogenetic development known from other, closely related species, the adult morphology of which would be able to accommodate them in other genera so that Calodiscus must be regarded as demonstrating a morphological blueprint within the lineage (see Lochman 1956, for an early discussion of the problem). Order Redlichiida Richter 1932 Superfamily Ellipsocephalacea Matthew 1887 Family Ellipsocephalidae Matthew 1887 Subfamily Protoleninae Richter and Richter 1948 Genus Protolenus Matthew 1892 Type species. Protolenus elegans Matthew 1892. Subgenus Hupeolenus Geyer 1990a Type species. Protolenus (Hupeolenus) hupei Geyer 1990a (by original designation). Protolenus (Hupeolenus) bergstroemi n. sp. (Figs. 6.1–18, 9.4?) Derivatio nominis. Named after the late Jan Bergstro¨m, for his eminent contribution to the knowledge on Palaeo- zoic arthropods. Holotype. Incomplete cranidium, FG 625/151a. Paratypes. Twelve incomplete cranidia and cranidial fragments under FG 625/142a, 142c, 145a, 150a, 150c, Fig. 5 Fossiliferous limestone layers in high frequency shale–sand- 151b, 151e, 151f, 151 g, 151 h, 152a, and 153c; three stone alternations of borehole 1209/78. 1 Thin lumachellic-bioclastic incomplete thoracic segments under FG 625/141a, 145b, limestone layer (trilobite coquina); polished vertical section of drill core. 2 Relatively thick limestone layer as a result of high-energy and 146b; one fragment of a librigenal spine assigned to P. deposition after storm events with indication of polyphase deposition (H.) bergstroemi under FG 625/145c. All locotypic. and diagenetic overprint; polished vertical section of drill core with 3 cm scale. 3 Detail of 1, showing partly well-preserved transverse Type locality and horizon. Drill core 1209/78, west of sections of trilobite cranidia (probably of Cambrunicornia saxonica n. Doberlug–Kirchhain and south of Herzberg, horizon at sp.) and numerous transported fragments of trilobite sclerites and depth of 303.5 m. shell hash Diagnosis. Species of Hupeolenus with relatively broad Material which perfectly matches the specimen from glabella; a weakly developed diagonal depression on the the Herzberg drill core has been described from the Jbel fixigena; a sagittally narrow preglabellar field of less than Wawrmast Formation of the Moroccan High Atlas or approximately two-thirds anterior border width (sag.) in

123 246 G. Geyer et al.

Fig. 6 Protolenus (Hupeolenus) bergstroemi n. sp. All specimens c from drill core 1209/78. Scale bars equal 1 mm. 1, 6, 9, 11,FG 625/151a, holotype, incomplete cranidium, partly exfoliated, with conspicuous caeca on preglabellar ﬁeld and preocular areas; longi-

Hyolith genus and species undet. A tudinal fracture created by compaction; 1 dorsal view, 6 anterior view, 9 right lateral view, 11 detail of anterior cranidium, note caeca developing from well developed parafrontal lobe. 2, 4 FG 625/153c, paratype, incomplete immature cranidium, partly exfoliated, with approximately subparallel glabellar sides, 2 dorsal view, 4 right lateral view, 3, 5, 8 FG 625/151b, paratype, immature cranidium, x x x x Trematobolus sp. A partly exfoliated; note dense granulation of preglabellar field and preocular areas and long palpebral lobes reaching level of posterior border furrow, 3 dorsal view, 5 anterior view, 8 left lateral view, 7 FG 625/151e, paratype, incomplete immature cranidium, latex cast of partly exfoliated internal mould; dorsal view has convex preocular areas and separation of eye ridges from palpebral lobes, 10 FG x xxx Acrotretoid genus and species undet. A 625/150a, paratype, fragment of large cranidium, partly exfoliated; note dense granulation. 12 FG 625/151 h, paratype, cranidial fragment, latex cast of external mould. 13 FG 625/145a, paratype, incomplete cranidium, detail showing prosopon with slightly transverse elongated granules on preglabellar field and pattern of terrace ridges on anterior border, 14 FG 625/146b, paratype, incomplete Trilobite genus and species undet. B thoracic segment, partly exfoliated, with large granules on axial ring and small granules on pleura and porous pattern on internal mould, and smooth surface of sagittal broad articulating half-ring, 15 FG 625/151f, paratype, cranidial fragment, latex cast of partly exfoliated anterior portion showing distinct, branched caeca on preglabellar field and preocular areas and delicate terrace ridges on anterior half of xx Trilobite genus and species undet. A anterior border, 16 FG 625/142a, paratype, cranidial fragment, detail

? showing different sizes of granules on ﬁxigena, 17 FG 625/145b, paratype, incomplete axial ring of thoracic segment with slight median transverse swelling in axial furrow, 18 FG 625/141a, paratype, incomplete axial ring of anterior thoracic segment, partly todraensis exfoliated, shows slightly forward swing of smooth articulating half-

Ornamentaspis aff. ring and corresponding curvature of transverse furrow

adult individuals; a low, broad and uniform anterior border

n. sp. with almost ﬂat dorsal face; and conspicuous caeca in large individuals.

Cambrunicornia saxonica Description. Cephalon subsemicircular in adult individuals, cranidial length/width ratio in large individuals ca. n. sp. ) 0.85; normal sized cephala with anterior margin moderately curved. Posterior margin s-shaped laterally of occipital ring and adaxially of cephalic suture, in general

Hupeolenus directed normal to axis. Protolenus ( bergstroemi Glabella moderately convex in transverse section, length ? ca. 85 % cephalic length and occipital ring width ca. 40 % maximum cranidial width across centre of palpebral lobes in large individuals; glabella slightly tapering forward, n. sp. A Calodiscus slightly constricted at glabellar furrows, maximum width across occipital ring in large individuals approximately 1.5

Depth (m) times width across frontal lobe (except parafrontal lobe). Frontal lobe distinctly convex in transverse proﬁle, glabellar front with relatively narrow curvature compared with total size of the glabella, framed by a usually well recog-

Thickness (cm) nizable and comparatively thick parafrontal band of sub- Size and depth of the studied fossiliferous samples in the core of drill hole 1209/78 equal thickness throughout, separated from frontal lobe by only a shallow furrow (Fig. 6.11). S1 well impressed, commences at axial furrows, distinctly curved backward, 1209-1531209-152 1 2 303.5 303.5 x x x 1209-1511209-150 4 4 303.5 309.3 x1209-141 x 0.2 342.9 x x x x 1209-1491209-148 101209-147 31209-145 51209-146 0.5 309.31209-144 2.5 309.31209-142 4 309.3 309.31209-143 1 309.3 0.51209-135 x 328.7 3.5 334.8 334.8 x 342.9 x x x x x x x x Table 1 Sample no.

123 A new lowermost middle Cambrian 247

123 248 G. Geyer et al. clearly disconnected medially. S2 similar, but directed Fig. 7 Cambrunicornia saxonica n. sp. All specimens from drill core c slightly less strongly backward; S3 shallower than S1 and 1209/78. Scale bars equal 1 mm. 1, 4, 7, FG 625/148a, paratype, incomplete cranidium, partly exfoliated; 1 dorsal view, 4 anterior S2, shorter and only slightly backward directed. Occipital view, 7 slightly oblique lateral view, 2 FG 625/146d, paratype, latex furrow consists of well impressed, relatively sharp lateral cast of partial immature cranidium, external mould with small sections which are only slightly backward directed, and a remains of the test, 3 FG 625/148d, paratype, latex cast of partial much shallower, broad median section with a slight for- cranidium, external mould, 5 FG 625/144b, paratype, latex cast of partial cranidium, internal mould, 6 FG 625/151c, paratype, incom- ward curvature, which tends to be obscure in some speci- plete thoracic segment; note different density of granules on axial ring mens. Occipital ring distinctly convex in transverse and pleura, lenticular shape of articulating half-ring, and prominent section, with thick and low median tubercle at subterminal fulcral thorn, 8, 10, 11 FG 625/146a, holotype, incomplete cranidium, position. Posterior margin of occipital ring with moderate partly exfoliated, 8 slightly oblique anterior view, 10 lateral view, 11 dorsal view, 9, 12 FG 625/142e, paratype, latex cast of partial overall curvature, projects well beyond posterior border. cranidium, external mould with test fragments, 9 dorsal view, 12 Axial furrows shallow and fairly narrow, generally lateral view, 13 FG 625/142b, paratype, cranidial fragment, internal defined from fixigenae by rapid slope to the groove-like mould; detail shows fine punctuation of anterior border, left preocular depression, deepest close to L3 and S3. Fixigena trape- area and preglabellar field. 14, FG 625/146c, paratype, incomplete librigena with preserved test, 15 FG 625/148b, paratype, latex cast of zoidal, in normal-sized to large individuals approximately cranidial fragment, external mould, showing well preserved palpebral 19–23 % maximum cranidial width across palpebral lobes, lobe, palpebral furrow and adjacent distal part of fixigena; note fine slightly convex in total, but with faint diagonal depression; granulation grading into smooth surface of palpebral lobe, 16 FG continues into short and narrow posterolateral projection 625/144a, paratype, cranidial fragment, largely exfoliated that extends transversely beyond the level of the visual surface at the posterior end of the palpebral lobe. Low, broad swelling present at posteroproximal corner of fixi- slight node-like swelling posterior to the end of the pal- gena adjacent to occipital furrow. Palpebral lobe moder- pebral furrows, strongly convex, markedly curves forward ately long, slightly oblique to exsagittal axis, varies in and ventrally from swelling; posterior margin is s-shaped. exsagittal length between ca. 25 and 30 % cephalic length Posterior border furrow moderately deep, normal to axis or in adult specimens, up to slightly more than 40 % cephalic directed slightly forward, expands distally from axial length in juvenile specimens; moderately wide, approxi- furrows. mately 5–8 % maximum cranidial width in adult individ- Facial suture with strongly diverging anterior branches, uals, up to 13 % in juveniles, faintly growing in width from strongly curved toward axis when reaching anterior border. anterior tips toward maximum breath near posterior ends, Anterolateral corner of cranidium projects to approxi- sausage-shaped, more or less uniformly convex in trans- mately the distal margin of palpebral lobe. Posterior verse section and not divided into internal and external braches of suture ventrally directed, slightly diverging in lobes. Palpebral furrow readily visible although fairly ventral view, with gentle convex curvature. shallow, more or less uniform in width throughout, but Thorax known only from fragments of disarticulated with broadest portion at midlength; proceeds with clear segments. Axial ring moderately convex in transverse sec- angular bend into a narrow and shallow furrow that sepa- tion, with well impressed or even deep transverse furrow; rates palpebral lobe from eye ridge. Eye ridge a low but postannulus with weak sagittal convexity, but relatively distinct, straight lobe slightly oblique to axis, slightly lower steep anterior face; weak median axial node present in some than palpebral lobe and separated by a small angle as well, segments at least. Articulating half-ring moderately broad, moderately long, clearly separated by the axial furrow from and gently and equally convex in sagittal section in anterior the glabella, but projects as very shallow ocular line across segments, approximately two-thirds sagittal breadth of axial furrow to connect with the parafrontal band. postannulus (Fig. 6.18), enables moderately strong inflex- Anterior border well developed, slightly convex or bar- ion of adjacent segments; broader at posterior segments and like and nearly flat in transverse section, fairly wide, ca. with distinctly curved anterior margin (Fig. 6.14). 9–11 % cephalic length in large specimens, up to 12 % Pleura with straight anterior margin more or less per- cephalic length in juveniles, more or less equal in width up to pendicular to the length axis up to a distinct fulcral point the facial suture. Posterior margin of anterior border slopes approximately midlength of the transverse distance, rapidly to preglabellar field, but without a distinctly incised directed slightly rearward from this point and finally anterior border furrow in adult individuals. Preglabellar field swinging into a narrow, moderately long pleural spine. narrow (sag.), ca. 5–7 % cephalic length. Preocular field Posterior margin straight or faintly curved, swings forward subtrapezoidal, slightly convex in small individuals, almost to define a small indention at the base of the pleural spine. flat in large specimens, sloping toward anterior. Pleural furrow fairly broad, moderately deep, with slightly Posterior border relatively narrow to moderately broad shallower slope at posterior part and steeper slope anteri- (exsag.), growing in width from the axial furrows to a orly, commences close to anterior margin at axial furrow 123 A new lowermost middle Cambrian 249

123 250 G. Geyer et al. but more or less central to pleuron for most of the distance, Chains have characters which are also visible in Protolenus fades in subcentral position close to base of the pleural (H.) bergstroemi, for example the conspicuous network of spine at approximately three-fourths of the pleural length. caeca on the preocular areas (Gozalo et al. 2007, p. 367, Librigena known only from a fragment showing a ca. Fig. 5G). Differences in the Spanish material, however, can 9.5 mm long, slender, weakly curved genal spine assigned be recognized in the presence of a furrow from the proxi- to the species. Rostral plate, hypostome and pygidium mal ends of the eye lobes toward the anterior border furrow unknown. and a sagittally broader preglabellar field. Dorsal surface of glabella, fixigenae, preglabellar field, Protolenus (H.) dimarginatus Geyer 1990a, a species and preocular areas covered by medium-sized granules confined to the Morocconus notabilis Zone in the Moroc- (Fig. 6.13, 16). Preglabellar field and preocular areas can can Atlas ranges and also known from the Valdemiedes be covered by a conspicuous network of branched caeca in Formation in the Iberian Chains, is easily distinguished by a centrifugal pattern (Fig. 6.11, 15). Caeca may also be the characteristic subdivision of the very broad anterior present on the fixigenae. Anteromarginal portions of the border into two bands. The type species of Hupeolenus, P. anterior cephalic border covered by terrace ridges (H.) hupei Geyer 1990a, is a smaller species with a nar- (Fig. 6.13, 15), its posterior portions close to the slope to rower glabella; a better developed diagonal furrow on the the border furrow sometimes carry granules. Terrace ridges fixigena; distinct corner furrows; a broader preglabellar sometimes present on the anterior part of the glabella. field; a more prominent anterior border; and relatively Thoracic axial ring with moderately coarse granules, indistinct caeca on the preocular areas. That species is, in pleurae finely granulose, furrows smooth (Fig. 6.14). fact, the index fossil for the Moroccan Hupeolenus Zone. Protolenus (Hupeolenus) mckillopi Fletcher 2003 from Discussion. Protolenus (Hupeolenus) bergstroemi n. sp. the Brigus Formation of Avalonian southeastern New- has characters typical of the subgenus Hupeolenus, for foundland is characterized by wide fixigenae and a low example the fairly low and sagittally broad anterior border, anterior border, which is barely raised above the pregla- the nearly parallel posterior part of the glabella, and a bellar field and which has small but distinct punctae feeble diagonal depression on the fixigena. The relatively (Fletcher 2003, pl. 97, pl. 3, Figs. 18–20). This species, large size, the comparatively wide glabella, and the con- however, has a glabella with a shape that is fairly charac- spicuous caeca in large individuals may be counted as teristic for the subgenus Protolenus (Protolenus) and could rather typical of the subgenus Protolenus, but the noted be regarded as a morphological link between the type Hupeolenus characters are certainly much more distinct. subgenus and Hupeolenus. Protolenus (H.) bergstroemi most closely resembles Pro- tolenus (H.) termierelloides Geyer 1990a, a species first Genus Cambrunicornia Geyer 1990a described from the upper Hupeolenus and lower Morocc- Type species. Cambrunicornia vanlooyi Geyer 1990a. onus notabilis zones of the Lemdad Syncline in the Moroccan High Atlas (Geyer 1990a, p. 186–187, Fig. 64, Cambrunicornia saxonica n. sp. pl. 47, Figs. 1–8; Geyer et al. 1995, p. 79, 88, 89; and (Fig. 7.1–16) Geyer and Landing 2006, p. 79, 88, 89). Protolenus (H.) Derivatio nominis. Named after the state of Saxony, as a bergstroemi differs from P. (H.) termierelloides in the reference to its location. slightly wider glabella; a more weakly developed diagonal depression on the fixigena; the absence of a recognizable Holotype. Incomplete cranidium FG 625/146a (Fig. 7.8, ‘‘corner furrow’’ (a furrow from the proximal ends of the 7.10, 7.11). Paratypes. Eleven cranidia and cranidial eye lobes toward the anterior border furrow close to the fragments under FG 625/142b, 142e, 144a, 144b (coun- suture); a sagittally narrower preglabellar field in adult terpart of 144a), 146d, 148a, 148b, 148c, 148d, 149b, 150b, individuals (despite notable differences during ontogenetic and 153e; one incomplete thoracic segment under FG development); and the more pronounced network of bran- 625/151c; one incomplete librigena under FG 625/146c. ched caeca in the large individuals of the species, at least. It All locotypic. is emphasized that some of these features may be enhanced Type locality and horizon. Drill core 1209/78, west of by the different types of preservation and the larger size of Doberlug–Kirchhain and south of Herzberg, horizon at the adult individuals in the TDS material. depth 303.5 m. Protolenus (H.) termierelloides has subsequently been reported from the Valdemiedes Formation of the Iberian Diagnosis. Species of Cambrunicornia with strongly con- Chains, northern Spain (Dies et al. 2001; Gozalo et al. 2007 vex, distinctly and more or less equally tapering glabella; and Linãń et al. 2008), but these assignments remain ten- fairly distinct glabellar furrows on the shell exterior; frontal tative, and the illustrations of specimens from the Iberian lobe with thick node or spine; occipital ring clearly convex

123 A new lowermost middle Cambrian 251 in sagittal profile, with evenly curved posterior margin; convexities between fixigena and palpebral lobe; proceeds preglabellar field distinctly convex. into shallow depression that separates palpebral lobe from eye ridge. Eye ridge a low but distinct, faintly curved ridge Description. Cephalon subsemicircular in adult individu- slightly oblique to axis, describes a distinct angle to the als, cranidial length/width ratio in normal sized individuals palpebral lobe, clearly separated by the axial furrow from ca. 0.80; anterior margin moderately to pronouncedly the glabella. curved. Posterior margin more or less straight abaxial of Anterior border narrow (sag.), ca. 8–9 % cephalic length occipital ring, directed normal to axis. in adult specimens, slightly convex in transverse section, Glabella strongly convex in transverse section, distinctly more or less equal in width up to the facial suture. Anterior and more or less equally tapering forward from S1, length border furrow a shallow indistinct groove ill-defined from ca. 80 % cephalic length and occipital ring width ca. the preglabellar field and preocular areas. Preglabellar field 37–40 % maximum cranidial width across centre of pal- moderately broad (sag.), ca. 15 % cephalic length, slightly pebral lobes in adult individuals; maximum width across convex. Preocular field subtrapezoidal, slightly to moder- occipital ring in large individuals nearly 1.5 times width ately convex, sloping toward anterior border furrow. across frontal lobe (except parafrontal lobe). Glabella with Posterior border moderately broad (exsag.), faintly slightly curved profile in lateral view, but frontal lobe with growing in width from axial furrows to a slight node-like distinct swelling or node, glabellar front with relatively swelling posterior to the palpebral furrow, strongly convex, narrow curvature and with low, more or less fused and curves forward and deflected ventrally from swelling. often obsolescent parafrontal band. Glabellar furrows Posterior border furrow a moderately deep, relatively broad shallow to moderately impressed on the test, well impres- groove normal to axis or directed slightly forward, slightly sed on internal moulds; S1 commences at axial furrows, expands distally from axial furrows. slightly curved and distinctly directed backward, discon- Facial suture with distinctly diverging anterior branches, nected medially. S2 similar, faintly curved and slightly less curved toward axis slightly posterior to anterior border strongly backward directed; S3 similar, slightly shallower furrow. Anterolateral corner of the cranidium projects to, than S1 and S2, slightly backward directed, tends to pro- approximately, the distal margin of the palpebral lobe. ceed as a very shallow depression across the midline. Posterior braches of suture ventrally directed, slightly Occipital furrow consists of well impressed, sharp lateral diverging in ventral view, with gentle convex curvature. sections almost normal to axis, and a slightly shallower and Librigena known only from a nearly complete small slightly broader median section. Occipital ring distinctly sclerite consisting of a moderately broad (tr.) librigenal convex in transverse and sagittal section; its posterior platform, moderately convex lateral border, and a relatively margin with moderate overall curvature, projects well prominent eye socle. No librigenal spine developed. The beyond posterior border. lateral border furrow is a shallow and fairly narrow trough, Axial furrows fairly narrow, more or less defined by which fades posteriorly toward the suture. The furrow changing convexities, a low groove-like depression for which separates the eye socle from the librigenal platform short sections. Fixigena trapezoidal with slightly curved is formed only by a change in convexity. The posterior anterior and anterolateral margins, in adult individuals branch of the suture is nearly straight. The lateral margin approximately 40 % cephalic length and approximately curves adaxially in a narrow bent to create a sharp corner. 22–26 % maximum cranidial width across palpebral lobes, Thorax known only from two fragments of disarticu- continues into short and narrow, strongly ventrally defected lated segments. Axial ring moderately convex in transverse posterolateral projection that extends transversely beyond section, with well impressed transverse furrow; postannu- the level of the visual surface at the posterior end of the lus with moderate sagittal convexity and slight median palpebral lobe. Low, broad swelling present at postero- swelling. Articulating half-ring relatively broad and len- proximal corner of fixigena adjacent to occipital furrow. ticular in dorsal view, approximately two-thirds sagittal Palpebral lobe moderately long, slightly oblique to exsag- breadth of postannulus (Fig. 7.6), with distinctly curved ittal axis, varies in exsagittal length between ca. 25 and anterior margin so that a strong flexion of adjacent seg- 30 % cephalic length in adult specimens; moderately wide ments could be performed. (approx. 5–8 % maximum cranidial width in adult indi- Pleurae with straight anterior margin more or less per- viduals), developed as distinctly upturned surface oblique pendicular to the length axis, swinging anteriorly toward a to the vertical axis, lenticular in dorsal view with moder- distinct acute fulcral point at approximately two-thirds the ately curved adaxial margin and more strongly curved transverse distance, directed rearward from this point to margin at suture to the visual surface, slightly convex in develop into an acute pleural spine. Posterior margin longitudinal profile. Palpebral furrow shallow, on the straight or faintly curved. Pleural furrow fairly broad, external surface of the test marked only as change in moderately deep, with shallow slope at posterior part and 123 252 G. Geyer et al. somewhat steeper slope anteriorly, commences close to Additional material of Cambrucornia been described by anterior margin at axial furrow to swing into a subcentral A´ lvaro (2007, Fig. 4G–I) from the Cantabrian Mountains position in the pleuron for most of the distance and swing as ‘‘Cambrunicornia? sp.’’ The description is based on a obliquely rearward into the base of the pleural spine. single specimen of probably an immature individual, which Rostral plate, hypostome and pygidium unknown. resembles Cambrunicornia agdziensis in most respects, but Dorsal surface of glabella, fixigenae, preglabellar field, has a more strongly convex glabella. The specimen from preocular areas and librigenal platform densely covered by the Cantabrian Mountains has been recovered from the top granules, which are relatively coarse on the glabella and of the lower member of the Lańcara Formation, which is smaller on the other parts of the cranidium (Fig. 7.3, 15). assigned to the top of the Bilbilian of the Iberian regional Internal moulds finely punctuate (Fig. 7.13). Anterior scheme and thus below the first Paradoxides assigned to P. border nearly smooth or with fairly long terrace ridges mureroensis. This level corresponds again to the lower parallel to the cephalic margin, lateral border with long, Agdzian of the West Gondwanan standard and the Hu- subparallel terrace ridges, librigenal corner with faint peolenus to lowermost Morocconus notabilis zones. wrinkles, furrows with low, small granules. Terrace ridges Subfamily Ellipsocephalinae Matthew 1887 sometimes present on the anterior part of the glabella (Fig. 7.4). Thoracic axial ring with moderately coarse Ornamentaspis? aff. todraensis Geyer 1990a granules, pleurae finely granulose, furrows smooth or finely (Fig. 8.1–3) granulose. Material. Single incomplete cranidium, partly exfoliated, Discussion. Cambrunicornia saxonica n. sp. is morpho- under FG 625/153d. logically very similar to Cambrunicornia vanlooyi Geyer Locality and horizon. Drill core 1209/78, west of Do- 1990a, the type species of the genus. This species from the berlug–Kirchhain and south of Herzberg, horizon at depth Morocconus notabilis Zone of the central Anti-Atlas of of 303.5 m. Morocco has a slightly narrower glabella and occipital ring with a more acute front and a low, but relatively distinct Description. Cranidium with length/width ratio of ca. swelling on the preglabellar field, whereas the preglabellar 0.85; anterior margin pronouncedly curved; various parts field in C. saxonica is of normal convexity following that of cranidium relatively smooth, separated from each in the preocular fields or is even slightly sunken. In addi- other merely by changes in convexity; distinct furrows tion, the occipital ring in C. saxonica is distinctly convex in absent; glabella and the unit of preglabellar field and sagittal profile (rather than low convexity as in C. vanlooyi) anterior border approach a similar overall convexity in and tapers less toward axial furrow. The anterior border in lateral profile. Glabella moderately convex in transverse C. vanlooyi is obsolescent in front of the glabella. All section, distinctly and more or less equally tapering known specimens of C. vanlooyi with preserved exterior of forward, length ca. 70 % cephalic length; width across the test appear to have been smooth, whereas the test in C. L1 slightly less than 40 % maximum cranidial width saxonica is finely granulose. across centre of palpebral lobes; glabellar maximum Cambrunicornia agdzensis Geyer 1990a, also from the width ca. 1.5 times width across frontal lobe; glabellar Morocconus notabilis Zone of the Jbel Wawrmast For- front equally rounded. Glabellar furrows obsolescent, mation in the central Anti-Atlas, is clearly differentiated by faintly indicated as three pairs of low broad depressions. its slightly upturned anterior border and a number of Occipital furrow consists of shallow, poorly defined lat- additional characters that need not to be discussed herein. eral furrows and a median faint to obsolescent transverse An additional species has been described as Cambr- depression. Occipital ring not completely preserved, unicornia? jafnaensis Elicki and Geyer 2012 from the obviously moderately broad (sag.), convex in transverse Numayri Member of the Burj Formation in Jordan, which and sagittal section; its posterior margin probably with is regarded as approximately coeval with strata of the moderate overall curvature, projects well beyond poster- Morocconus notabilis Zone of Morocco. The species from ior border. Jordan shares the type of distinctly tapering, highly convex Axial furrows developed as moderately broad, fairly glabella with a narrow frontal lobe and a protolenoid pat- shallow concave troughs between the glabella and the tern of three pairs of obliquely backward directed glabellar fixigenae, ill-defined from the latter. Fixigena form semi- furrows and a transverse occipital furrow, but lacks the circular, convex areas with their most prominent point node or spine on the glabellar frontal lobe and has a Pro- close to the palpebral furrows, approximately 40 % tolenus-type of fixigenae with small bacculae on the pos- cephalic length and 20 to 25 % maximum cranidial width teroproximal portions and weakly raised distal portions across palpebral lobes; posterolateral parts not preserved. separated by a shallow depression. Palpebral lobe moderately long, slightly oblique to

123 A new lowermost middle Cambrian 253

oblique to axis, meets axial furrow opposite to anterolateral corners of the glabellar front. Anterior border, preglabellar field and preocular fields fused to a sagittally and transversely convex unit of slightly less than 30 % cephalic length (tr.). Posterior border and border furrow not preserved. Facial suture with nearly subparallel, ventrally directed anterior branches; posterior braches of suture ventrally not preserved. Thorax, librigena, rostral plate, hypostome and pygidium unknown. Dorsal surface of test smooth. Discussion. The single incomplete cranidium has charac- teristics of the Ellipsocephalinae, and particularly of the morphologically smooth group with genera such as Elli- psocephalus Zenker 1833, Kingaspidoides Geyer 1990a, Ornamentaspis Geyer 1990a, and Latikingaspis Geyer 1990a. However, distinct differences exist for all of these genera, particularly in the more strongly tapering glabella with comparatively narrow (tr.) frontal lobe without distinct anterolateral ‘‘corners’’ or even ‘‘winglets.’’ The overall convexities in transverse and sagittal/exsagittal directions fit largely with those found in the species of Kingaspido- ides, but the fairly distinct depression which separates the frontal lobe from the convex preglabellar field does not exist in Kingaspidoides in such quality. A morphologically similar species has been described as Ornamentaspis? todraensis Geyer 1990 from the lower Middle Cambrian of the eastern Anti-Atlas, from a horizon which probably belongs to the Morocconus notabilis Zone. This species from the Anti-Atlas shares the tapering glabella and the distinct depression in front of the glabella and the kingaspidoid type of fixigenae and palpebral lobes. Even the proportions are similar in dorsal view. Differences exist, however, in the clearly more pronounced overall convexity of the Saxothuringian cranidium in sagittal direction, and a more dorsally projecting occipital ring in Ornamentaspis? todraensis. This occipital ring even projects into a fairly long terminal spine. Such a spine may have been developed in the Saxothuringian cranidium also, but most probably of a distinctly smaller size, if present at all. Additional kingaspidoid species with a somewhat tapering glabella and similar morphologies are known from Baltica, where they are described under such names as Proampyx sularpensis Ahlberg and Bergstro¨m 1978, Pro- Fig. 8 Ornamentaspis? aff. todraensis Geyer 1990a. FG 625/153d, ampyx grandis Ahlberg and Bergstro¨m 1978, and Stren- incomplete cranidium, partly exfoliated. 1 dorsal view, 2 right lateral view, 3 oblique anterior view. From drill core 1209/78. Scale bars uaeva? kullingi Ahlberg and Bergstro¨m 1978 and await equal 1 mm revision. Order and family uncertain exsagittal axis, ca. 30 % cephalic length; moderately wide, Genus and species undetermined A with low overall convexity. Palpebral furrow a very shallow groove. Eye ridge a low, indistinct, ill-defined ridge (Fig. 9.6)

123 254 G. Geyer et al.

Fig. 9 Trilobites from drill core 1209/78. Scale bars equal 1 mm. 1, meshes; 3, FG 625/135b, counterpart of FG 625/135a. 4, Protolenus 5, Calodiscus? n. sp. A, FG 625/146e, partial cranidium, dorsal and (Hupeolenus) bergstroemi n. sp.?, FG 625/145c, fragment of librig- oblique posterior views. 2, 3, 7, Genus and species undetermined B; 2, enal spine. 6, Genus and species undetermined A, FG 625/135d, 7, FG 625/135a, fragment of a sclerite interpreted as hypostome, sclerite fragment. 8, Hyolith genus and species indeterminate A, FG entire specimen and detail showing quasi-honeycomb pattern of 625/143b, internal mould of operculum

Material. Single fragment under FG 625/135d. Material. Single fragment, preserved as internal mould and counterpart with recrystallized shell, under FG Locality and horizon. Drill core 1209/78, west of Do- 625/135a and FG 625/135b (counterpart). berlug–Kirchhain and south of Herzberg, horizon at depth of 342.9 m. Locality and horizon. Drill core 1209/78, west of Doberlug–Kirchhain and south of Herzberg, horizon at Description and discussion. The only available material is depth of 342.9 m. a single small fragment of a trilobite sclerite. The specimen has transverse width of more than 4 mm and indicates a Description and discussion. The single specimen is a length of probably more than at least 12 mm, with distinct large fragment of ca. 21 9 13 mm in size, the margins of it transverse convexity. The only visible details are moder- preserved only as broken edges so that the true shape is ately coarse, fairly eroded terrace ridges (crest distance ca. unknown. Most is a more or less uniform shield of low to 0.3 mm), in a subparallel to apparently anastomosing pat- moderate convexity, bound by obliquely backward directed tern. The distinct erosion of the terrace ridges is surprising and weakly curved shallow furrows. The sclerite is covered if compared with the fairly good preservation of small with delicate configuration of ridges in a quasi-honeycomb details in other trilobite sclerites of the samples so that the pattern with mesh of the order of ca. 0.5 mm wide. specimen may testify a secondary deposition. The sclerite is interpreted as the remains of a large The identity of the specimen is difficult to indicate, but hypostome. The morphology resulting from this interpreta- the shell fragments resemble rostral plates known in par- tion does not immediately match known sclerites of trilobites adoxidine trilobites. Alternatively, it may be a part of the occurring in this stratigraphic interval of West Gondwana. ventral side of a large librigenal spine of a paradoxidine. The relatively significant honeycomb pattern is known best However, the ornamentation of this fragment also resem- from species attributed to the olenellid genus Wanneria bles patterns seen in trilobites, for example Myopsolenites Walcott 1910, which, however, would not have such a type of palmeri (Elicki and Geyer 2013) so that confident identi- hypostome. A similar prosopon is known from a specimen fication of even the higher taxon is not possible. described as Callavia hastata Raw 1936 from the Avalonian Red Callavia sandstone (Ac2 horizon) of Comley, Shrop- Genus and species undetermined B shire, a distinctly older olenelline trilobite now dealt with as (Fig. 9.2, 3, 7) Callavalonia callavei (Lapworth 1888; Lieberman 2001).

123 A new lowermost middle Cambrian 255

Phylum Brachiopoda Dume´ril 1806 of even genus level. Nonetheless, it is assumed herein that the best preserved specimens (described below) represent ven- Class Lingulata Goryansky and Popov 1985 tral and dorsal valves of the same species. Order Acrotretida Kuhn 1949 Shell material phosphatic. The best preserved ventral Superfamily Acrotretidae Schuchert 1893 valve (FG 625/142d) is small (ca. 1.3 mm wide), conical, with subcircular commissural outline and its greatest Acrotretoid genus and species indeterminate A transverse width slightly posterior to midlength. The (Fig. 10.1–4) postlarval shell is characterized by weakly preserved con- Material. Single ventral valve under FG 625/142d, single centric fila. The poor preservation does not enable deter- dorsal valve under FG 625/152b. Two poorly preserved mination of its generic affinity, but the specimen has the dorsal valves under FG 625/151d and 143c. shape and attitude of genera such as Hadrotreta Rowell 1966 or Vandalotreta Mergl 1988, which are known from Locality and horizon. Drill core 1209/78, west of Do- approximately coeval strata in Bohemia, Sardinia, Mor- berlug–Kirchhain and south of Herzberg, horizons at occo, Nevada, and Greenland (Mergl 1988; Streng 1999; depths of 334.8 and 303.5 m. Mergl and Elicki 2004). Description and discussion. The samples include a few The best preserved specimen of a dorsal valve (FG mostly incomplete valves of acrotretoid brachiopods. The 625/152b) is a small, moderately convex shell ca. 1.8 mm preserved characters are insufficient to enable determination wide, with somewhat transversely oval commissural

Fig. 10 Acrotretoid genus and species indeterminate A, both spec- and right lateral views. 2, 4 FG 625/152b, dorsal valve, shell exterior imens from drill core 1209/78. Scale bars equal 1 mm. 1, 3 FG with slight abrasions; dorsal and left lateral views 625/142d, ventral valve with apical region partly exfoliated; ventral 123 256 G. Geyer et al. outline and its greatest transverse width at or slightly Dorsal valve widest at or slightly posterior to midlength, anterior to midlength. Postlarval shell with weakly pre- lateral margins evenly curved; shallow sulcus may extend served concentric fila. from umbo. Interior of dorsal valve with relatively weakly Two small and probably immature dorsal valves speci- defined visceral area; probable anterior diductor muscle mens (larger valve, FG 625/143c, ca. 1.5 mm wide, smaller scars visible as faint, longitudinally elongate to spindle- valve, FG 625/151d, ca. 1.1 mm wide) are tentatively shaped impressions; possible posterior adductor scars assigned to the same form. They have a maximum trans- located transverse to axis near the posterolateral margin of verse width slightly anterior to midlength; lateral margins the valve. more or less evenly curved; with conspicuous sagittal and Ornamentation consists of fine growth lamellae; radial transverse convexity; beak marginal, distinctly acuminate. ornamentation of weak plications or absent. Vascular Ornamentation consists of moderately coarse growth canals of the dorsal valve visible in specimen FG 625/147a lamellae, which are preserved as typically broken edges of forming faint to moderately well impressed grooves in thin laminae; radial ornamentation absent. different density in two bands parallel to the anterior and anterolateral margins (Fig. 11.2). Class Obolellata Williams et al. 1996 Remarkable is the complex mosaic-type fragmentation Order Obolellida Rowell 1965 of valves because of dorsoventral compaction (Fig. 11.7, 9). Family Trematobolidae Popov and Holmer 2000 Discussion. Unfortunately, well-preserved ventral valves with details of the pedicle groove and the anterior part of Genus Trematobolus Matthew 1893 the visceral platform are absent from the specimens studied Type species. Trematobolus insignis Matthew 1893. so that the specific affinity remains questionable. The species portrayed by this material differs from almost all of Trematobolus sp. A the well known species of Trematobolus so it may be a yet (Fig. 11.1–9) undescribed new species. The most similar species is T. borobiensis Linãń and Mergl 2001 from the Daroca For- Reposited material. Ten valves and fragments of valves; mation and the lower Valdemiedes Formation of the Ibe- seven dorsal valves under FG 625/147a, 147b, 147c, 149a, rian Chains, Spain. This species shares with the current 150d, 153a, and 153b (counterpart of 153a); three incom- specimens from the 1209/78 borehole the fairly smooth plete ventral valves under FG 625/141b, 143a, and 149c median sector, weak muscle impressions in the dorsal (depths are given in Table 1). valve, and the fairly small and variable posterior adductor Description. The preserved material of Trematobolus muscle scars in the ventral valve (which are still larger in T. valves is insufficient to precisely characterize the species. borobiensis), but differs in the apsacline rather than cata- However, three specimens show details of characters cline to procline pseudointerarea. Additional striking dif- which exclude the assignment to most of the known ferences from, particularly, the West Gondwanan species, species. for example T. simplex (Vogel 1962) from Spain (Linãń Valves dorsi-biconvex, with slightly flattened median and Mergl 2001), T. splendidus Geyer and Mergl 1995, T. sector, with rectimarginal commissure. Shell relatively cleidrius Geyer and Mergl 1995, and T. serotinus Geyer thick. Ventral valve subcircular, widest at midlength, with and Mergl 1995, all from the Moroccan Anti-Atlas, exist in evenly curved lateral margins. Beak marginal, distinctly the relatively narrow and weakly developed posterior acuminate. Particularly instructive for the internal mor- adductor muscle scars in the ventral valve (Geyer and phology is a fragment of a ventral valve (Fig. 11.8). It Mergl 1995). In addition, it has a weak median groove includes the pseudointerarea and adjacent parts and a small posterior to the pedicle foramen unlike most of the afore- part of the visceral platform. The ventral pseudointerarea is mentioned species, except for T. splendidus. Only a single apsacline, moderately high, broadly subtriangular in out- ventral valve is known of Trematobolus palaestinensis line, relatively small, and has indistinct growth lines; Richter and Richter 1941 from the Cambrian of the Dead median part of the pseudointerarea bears pseudodeltidium Sea area in Jordan. This valve seems to have had a trans- developed as distinct, narrow triangular sector; anterior verse outline (despite slight distortion). Otherwise it is border of pseudointerarea with pair of tooth-like small similar to T. splendidus but differs in a differently shaped nodes. The visceral area seems to be weakly defined in the pedicle groove. present specimens; paired posterior adductor muscle scars Of the many species from outside West Gondwana, relatively small and narrow, moderately incised, oblique at Trematobolus pristinus (Matthew 1895) appears similar, an angle of ca. 40° to the length axis along posterolateral but the shape of its ventral pseudointerarea is unknown. margin of the visceral area. Trematobolus kempanum (Matthew 1897) has a slightly

123 A new lowermost middle Cambrian 257

Fig. 11 Trematobolus sp. A. All specimens from drill core 1209/78. subsemicircular arrangement of vascular canals originating from the Scale bars equal 1 mm. 1, 4 FG 625/147b, dorsal valve, dorsal and distal ends of the vascula lateralia. 6 FG 625/153b, counterpart of FG lateral views; note delicate radial plications on lateral ﬂanks. 2 FG 625/153a, internal mould of partially exposed dorsal valve. 7 FG 625/147a, dorsal valve, view of valve interior with faint impressions 625/149c, ventral valve crushed by dorsoventral compaction. 8 FG of vascular and muscle scars, and corrugational grooves near margin. 625/141b, fragment of ventral valve; detail showing posterior and 3 FG 625/153a, dorsal valve, internal mould of partially exposed apical region. 9 FG 625/147b, incomplete valve crushed by dorso- valve with well preserved visceral platform. 5 FG 625/150d, ventral compaction incompletely preserved internal mould of ventral valve; note elongate outline and a more strongly acuminate ventral muscle scars. According to Walcott’s original drawings, beak, but also lacks a distinct sulcus. Its posterior adductor Trematobolus excelsis Walcott 1908 from the upper Lower muscle scars are long and thin in the ventral valve, and thus Cambrian Saline Valley Formation of the Waucoba very much resembles the material from Doberlug–Kir- Springs section, Saline Valley, Inyo County, California, chhain in that character. However, it has a low median also has thick posterior adductor muscle scars in the ventral groove posterior to the pedicle foramen (Popov and Hol- valve and a thick and long pedicle groove. Walcott’s ﬁg- mer 2000, Fig. 122.1a). Trematobolus insignis Matthew ures for the dorsal valve are indicative of remarkably low 1893, the type species of the genus from New Brunswick, convexity, and its shell interior seems to be unknown. is again imperfectly known, but seems to differ at least in Trematobolus bicostatus (Goryansky 1964) (originally the more strongly developed ventral posterior adductor described in Goryansky et al. 1964,asT. pristinus

123 258 G. Geyer et al. bicostatus), from the Toyonian of the Siberian Platform, and P. jilocanus zones; Dies et al. 2004) of the Iberian differs in having a less projecting beak and more con- Chains. Species of Cambrunicornia are known from the spicuous radial ornament. Its posterior adductor muscle lower Morocconus notabilis Zone of the Anti-Atlas, but scars differ substantially in being broadly elliptical. also occur in coeval strata in Jordan (Elicki and Geyer, 2013). The ellipsocephaline trilobite has its closest rela- Phylum? Mollusca Cuvier 1798 (non 1797) tives in species which also occur in the lowermost Middle Class Hyolitha Marek 1963 Cambrian strata of West Gondwana (lower Agdzian) and in Order Hyolithida Matthew 1899 slightly older strata of the Baltican Holy Cross Mountains (Zylin_ ´ska and Masiak 2007; Zylin_ ´ska and Szczepanik Family uncertain 2009) and Sweden (Ahlberg and Bergstro¨m 1978; Geyer Genus and species indeterminate A et al. 2004). Calodiscus? n. sp. almost certainly represents a species which is already known from the Morocconus (Fig. 9.8) notabilis Zone of the High Atlas Mountains of Morocco Reposited material. Incomplete operculum under FG (Geyer 1988). 625/143b. Trematobolus is a characteristic obolelloid brachiopod genus distributed with a number of species in a relatively Locality and horizon. Drill core 1209/78, west of Do- short stratigraphic interval of the traditional Lower–Middle berlug–Kirchhain and south of Herzberg, horizon at depth Cambrian boundary interval. It seems to have its maximum of 334.8 m. distribution in West Gondwana (Moroccan Atlas ranges, Description and discussion. The single cast of a small northern Iberia, Dead Sea region), but is also known from a hyolithid operculum is far too poorly preserved to enable few spot samples in the West Avalonian New Brunswick, confident assignment to a family, genus, or even species. and is possibly known from the upper Lower Cambrian of The specimen is semicircular in dorsal view and ca. the Death Valley region, California (Walcott 1908). Tre- 2.5 mm wide, with slightly inflated, collar-like conical matobolus insignis (Matthew 1893) and Trematobolus shield and equally curved posterior margin; remains of the pristinus (Matthew 1895) both come from the classical cardinal shield form a steep platform. In the sulcus-type Hanford Brook section of New Brunswick, where it process toward the cardinal shield the operculum resembles slightly predates, or co-occurs with, the Protolenus fauna an operculum described by Sdzuy (1970, pl. I, Fig. 3) from that includes species of Protolenus (Protolenus) (Matthew slightly younger strata of the Tro¨bitz Formation of the 1895; Westrop and Landing 2000). The stratigraphic level Doberlug borehole LS 1/63. Sdzuy (1970) assigned this of these species can be correlated with the Morocconus specimen as ‘‘Orthotheca aff. affinis Holm 1893.’’ This notabilis Zone of Morocco (Geyer 1990a). Trematobolus assignment is based on the shape of that operculum. The bicostatus (Goryansky 1964) comes from a number of current material differs not only in the semicircular shape sections in the Anabar Uplift of eastern Siberia and occurs but also the absence of distinct clavicula. in strata now assigned to the Toyonian (Goryansky et al. 1964). At least the upper Toyonian, however, correlates with the lower Agdzian stage of West Gondwana (Geyer Correlation and palaeogeographic relations and Peel 2011). It should further be emphasized that Trematobolus The fauna described herein unequivocally features the characterizes a particular distinctive situation in lithofacial lowest Middle Cambrian upper Hupeolenus and/or lowest development. The species of this genus are obviously fol- Morocconus Zone (lower Agdzian in the West Gondwanan lowing opportunistic live strategies as indicated by mass standard of Geyer and Landing 2004). Most significant are occurrences such as in the Moroccan Atlas ranges (Geyer the trilobite remains. Species of Protolenus (Hupeolenus) and Mergl 1995), so they tend to occur in mass assem- characterize the low diversity assemblages of the Hupeol- blages. Those strata with associations dominated by indi- enus Zone in the Moroccan Atlas regions, but range well viduals of Trematobolus species are typical of strata of into the overlying Morocconus notabilis Zone (Geyer transgressive systems tracts so that the genus is particularly 1990a, 1990b; Geyer and Landing 2004, 2006). The new representative of strata overlying stratigraphic hiatuses. species P. (H.) bergstroemi has its closest resemblance To summarize, the assemblages described are not only with P. (H.) termierelloides, which ranges from the upper the oldest known Middle Cambrian from the Lusatian/ Hupeolenus into the Morocconus notabilis Zone in the Saxonian segment of the Saxothuringian but also the oldest Moroccan High Atlas, but seems also to occur in the coeval Middle Cambrian fauna known from the Saxothuringian lower Valdemiedes Formation (Protolenus dimarginatus domain in general. All of the fairly well determinable

123 A new lowermost middle Cambrian 259 species have relatives in coeval strata of the typical West References Gondwanan realm, particularly in southern Morocco, from where Hupeolenus, Cambrunicornia, and Trematobolus Ahlberg, P., and J. Bergstro¨m. 1978. Lower Cambrian ptychopariid occur relatively frequently. They reconfirm the palaeoge- trilobites from Scandinavia. Sveriges Geologiska Underso¨kning, Avhandlingar och Uppsatser, I 4:o, Ser. Ca, 49. ographic position in the Perigondwanan segment. Ahlberg, P., and J. Bergstro¨m. 1993. The trilobite Calodiscus lobatus As noted above, the lithological characters suggest dif- from the Lower Cambrian of Scania, Sweden. Geologiska ferences from the typical Tro¨bitz Formation. In accor- Fo¨reningens i Stockholm Fo¨rhandlingar 115: 331–334. ´ dance, the numerous limestone intercalations with Alvaro, J.J. 2007. New ellipsocephalid trilobites from the lower Cambrian member of the Lańcara Formation, Cantabrian indication of high-energy conditions suggests high-fre- Mountains, northern Spain. Memoirs of the Association of quency sea-level changes, and Trematobolus as a potential Australasian Palaeontologists 34: 343–355. indicator of transgressive developments in the basin sug- Brause, H., 1969. Das verdeckte Altpalaözoikum der Lausitz und gests, also, that this part of the section may represent a late seine regionale Stellung. Abhandlungen der Deutschen Akade- mie der Wissenschaften Berlin, Klasse fu¨r Bergbau, Hu¨ttenwesen stage of subglobally recognizable eustatic sea-level fluc- und Montangeologie 1968 (1). tuations at the traditional Lower–Middle Cambrian Brause, H. 1970. Ein neuer wichtiger Aufschluß im Kambrium von boundary interval. Doberlug–Kirchhain. Geologie 19: 1048–1065. Brause, H., and O. Elicki. 1997. Kambrium. In Stratigraphie von Deutschland, II. Ordovizium, Kambrium, Vendium, Riphaïkum, Teil I. Courier Forschungsinstitut Senckenberg 200:308–322. Buschmann, B., 1995. Tectonic facies analysis of the Rothstein Conclusions Formation (Neoproterozoic, Saxothuringian Zone, E Germany). Unpublished Ph.D. Thesis, TU Bergakademie Freiberg. Numerous thin limestone horizons in a succession domi- Buschmann, B., U. Linnemann, J. Schneider, and T. Su¨ß. 1995. Die cadomische Entwicklung im Untergrund der Torgau–Doberluger nated by siliciclastics yield low to moderately diverse Synklinale. Zeitschrift fu¨r Geologische Wissenschaften 23: assemblages with trilobites and brachiopods, including the 729–749. new formally introduced herein species Protolenus (Hu- Buschmann, B., O. Elicki, and P. Jonas. 2006. The Cadomian peolenus) bergstroemi n. sp. and Cambrunicornia saxonica unconformity in the Saxo-Thuringian Zone, Germany: palaeogeographic affinities of Ediacaran (terminal Neoproterozoic) and n. sp. These faunas are the earliest to early Middle Cam- Cambrian strata. Precambrian Research 147: 387–403. brian lower Agdzian as recorded in areas with a nearly Cederstro¨m, P., P. Ahlberg, and E.N.K. Clarkson. 2005. Morphology, complete record of the Lower–Middle Cambrian boundary ontogeny, and enrollment of the Lower Cambrian eodiscoid interval (for example northern Spain and southern Mor- trilobite Calodiscus lobatus from Sweden. Geologiska Fo¨reningens i Stockholm Fo¨rhandlingar 127: 46. occo). Consequently, the gap currently recognized between Cederstro¨m, O., P. Ahlberg, E.N.K. Clarkson, C.H. Nilsson, and N. Lower Cambrian and Middle Cambrian rock successions in Axheimer. 2009. The lower Cambrian eodiscoid trilobite Cal- the northern segment of the Saxothuringian domain seems odiscus lobatus from Sweden: morphology, ontogeny and to have arisen solely as a result of incomplete biostrati- distribution. Palaeontology 52: 491–539 Cuvier, G., 1798. Tableau e´le´mentaire de l’histoire naturelle des graphic and lithostratigraphic data rather than the physical animaux. pp. i–xvi, 1–710. Paris: Baudouin. absence of strata because of non-deposition, or subsequent Dawson, J.W., 1868. Acadian geology. The geological structure, erosion. organic remains and mineral resources of Nova Scotia, New Remarkably, the thin limestone layers which yield the Brunswick, and Prince Edward Island, etc. 2nd edn. i–XXVII, 1–694. London: MacMillan and Co. macrofossils seem to indicate a transgressive development Dies, M.E., and R. Gozalo. 2004. Agnostida (Trilobita) de la and frequent sea-level changes and thus parallel the envi- Formacioń Valdemiedes (Leoniense: Ca´mbrico Medio basal) ronmental development seen in the coeval strata of the Jbel de las Cadenas Ibe´ricas (NE de Espanã). Boletıń Geolo´gico y Wawrmast Formation in southern Morocco which marks Minero 115: 683–698. Dies, M.E., R. Gozalo, and E. Linãń. 2001. Protolenus (Hupeolenus) the termination of the regressional events at the Lower– Geyer 1990 (Trilobita) en el Bilbiliense (Ca´mbrico Inferior) de Middle Cambrian boundary interval. Jarque (Zaragoza, Cadenas Ibe´ricas). In: Los Fo´siles y la Paleogeografıá. XVII Jornadas de la Sociedad Espanõla de Acknowledgments Preparation of this article was made possible by Paleontologıá, 18–20 de octubre 2001, vol. 5.2, 301–309. research grant GE 549/21-1 of the Deutsche Forschungsgemeinschaft Dies, M.E., R. Gozalo, and E. Linãń. 2004. Zonacioń del lı´mite (DFG) to G.G. Most of the photography and of the preparation was Bilbiliense–Leoniense (Formacioń Valdemiedes, Ca´mbrico performed in the research laboratory of J.S. Peel at Uppsala Uni- Inferior–Medio) en las Cadenas Ibe´ricas. Geo-Tema 6(2): versity, which is gratefully acknowledged. Sincere thanks are due to 283–286. A. Zylin_ ´ska, University of Warsaw, and R. Gozalo, Universitat de Dume´ril, A.M.C., 1806. Zoologie analytique, ou me´thode naturelle de Vale`ncia, Burjassot, for thorough review and helpful remarks on the classification des animaux, rendue plus facile a` l’aide de manuscript, to M. Streng, Uppsala University, for kind assistance and tableaux synoptiques. pp. i–xxxiii, 1–344. Paris: Allais. information on the acrotretoid specimens, and to E. Landing, New Elicki, O., 1992. Faziesanalyse der unterkambrischen Karbonate York State Museum, Albany, NY, for explanations of G.F. Matthew’s Deutschlands. Unpublished Ph.D. Thesis, TU Bergakademie original stratigraphic concepts. Freiberg.

123 260 G. Geyer et al.

Elicki, O. 1994. Lower Cambrian carbonates from eastern Germany: Geyer, G., and M. Mergl. 1995. Mediterranean representatives of the palaeontology, stratigraphy and palaeogeography. Neues Jahrbuch obolellid Trematobolus (Brachiopoda) and a review of the genus. fu¨r Geologie und Palaöntologie Abhandlungen 191(1): 69–93. Palaöntologische Zeitschrift 69(1/2): 179–209. Elicki, O. 1997. Biostratigraphic data of the German Cambrian— Geyer, G., and J.S. Peel. 2011. The Henson Gletscher Formation, present state of knowledge. Palaöntologie, Stratigraphie, Fazies North Greenland, and its bearing on the global Cambrian Series psf 4, Freiberger Forschungshefte C 466: 155–165. 2–Series 3 boundary. Bulletin of the Czech Geological Survey Elicki, O. 1999. Beitrag zur Lithofacies und zur Lithostratigraphie im 86(3): 465–534. Unterkambrium von Doberlug–Torgau. Palaöntologie, Stratigra- Geyer, G., E. Landing, and W. Heldmaier. 1995. Faunas and phie, Fazies psf 7, Freiberger Forschungshefte C 481: 107–119. depositional environments of the Cambrian of the Moroccan Elicki, O. 2007. Paleontological data from the Early Cambrian of Atlas region. In MOROCCO ‘95—the Lower–Middle Cambrian Germany and paleobiogeographical implications for the config- standard of western Gondwana, eds. Geyer, G., and E. Landing. uration of central Perigondwana. Geological Society of America Beringeria Special Issue 2:47–119. Special Paper 423: 143–152. Geyer, G., A. Popp, T. Weidner, and L. Fo¨rster. 2004. New Lower Elicki, O., and F. Debrenne. 1993. The Archaeocyatha of Germany. Cambrian trilobites from Pleistocene erratic boulders of northern Palaöntologie, Stratigraphie, Fazies psf 1, Freiberger Fors- Germany and Denmark and their bearing on the intercontinental chungshefte C 450: 3–40. correlation. Palaöntologische Zeitschrift 78(1): 127–135. Elicki, O., and G. Geyer. 2010. The faunal province of the southern Geyer, G., O. Elicki, O. Fatka, and A. Zylin_ ´ska. 2008. Cambrian. In margin of the Rheic Ocean. Cambrian biostratigraphy. In Pre- The geology of central Europe, vol. 1. Precambrian and Mesozoic Geology of Saxo-Thuringia—from the Cadomian Palaeozoic, ed. T. McCann, 155–202. London: Geological active margin to the Variscan Orogen, eds. Linnemann, U. and Society of London. R.L. Romer, 103–114. Stuttgart: Schweizerbart. Goryansky, V.Y., and L.E. Popov. 1985. Morfologiya, sistematich- Elicki, O., and G. Geyer. 2013. The Cambrian trilobites of Jordan— eskoe polozhenie i proiskhozhdenie bezzamkovykh brakhiopod c taxonomy, systematic and stratigraphic significance. Acta Geo- karbonatnoy rakovinoy [The morphology, systematic position logica Polonica 63(1): 1–56. and origin of the inarticulate brachiopods with calcareous shells]. Elicki, O., and T. Wotte. 2003. Cambroclaves from the Cambrian of Paleontologicheskiy Zhurnal’ 1985(3): 3–14. Sardinia (Italy) and Germany: constraints for the architecture of Goryansky, V.Yu., L.I. Egorova, and V.E. Savitsky. 1964. O faune western Gondwana and the palaeogeographical and paleoeco- nizhnego kembriya srednego sklona Anabarskogo shchita. logical potential of cambroclaves. Palaeogeography Palaeocli- Uchenie zapiskiy nauchno-issled. instituta geologii Arktiki matology Palaeoecology 195(1–2): 55–71. (NIIGA), seriya Paleontologiya i biostratigrafiya 4:5–32. Fletcher, T.P. 2003. Ovatoryctocara granulata: the key to a global Gozalo, R., E. Linãń, M.E. Dies A´ lvarez, J.A. Ga´mez Vintaned, and Cambrian stage boundary and the correlation of the olenellid, E. Mayoral. 2007. The Lower–Middle Cambrian boundary in the redlichiid and paradoxidid realms. Special Papers in Palaeon- Mediterranean subprovince. In The evolution of the Rheic tology 70: 73–102. Ocean: from Avalonian-Cadomian active margin to Alleghe- Franke, W. 1989. Tectonostratigraphic units in the Variscan Belt of nian–Variscan collision, eds. Linnemann, U., R.D. Nance, P. Europe. Geological Society of America, Special Papers 230: 67–90. Kraft, and G. Zulauf. Geological Society of America Special Freyer, G., and P. Suhr. 1987. U¨ ber Archaeocyathinen-Funde und den Paper 423:359–373. doi:10.1130/2007.2423(17). lithologischen Aufbau des Unterkambriums im Gebiet von Hall, J., 1847. Natural History of New York. Palaeontology, vol. 1. Torgau. Zeitschrift fu¨r Geologische Wissenschaften 15: 655–680. Containing descriptions of the organic remains of the lower Freyer, G., and P. Suhr, P. 1992. U¨ ber Algengemeinschaften aus der division of the New-York System. Albany: C. van Benthuysen. unterkambrischen Zwethauer Folge des Gebietes von Torgau. Holm, G., 1893. Sveriges kambrisk-siluriska Hyolithidae och Con- Freiberger Forschungsheft, C 445, Palaöntologie:49–65. ulariidae. Sveriges geologiska Underso¨kning, Afhandlingar och Geyer, G., 1988. Agnostida aus dem ho¨heren Unterkambrium und Uppsatser C 112. dem Mittelkambrium von Marokko. Teil 2: Eodiscina. Neues Howell, B.F. 1935. Cambrian and Ordovician Trilobites from He´rault, Jahrbuch fu¨r Geologie und Palaöntologie, Abhandlungen Southern France. Journal of Paleontology 9: 222–238. 177(1):93–133. Kobayashi, T. 1935. 935c. The Cambro-Ordovician formations and Geyer, G. 1990a. Die marokkanischen Ellipsocephalidae (Trilobita: faunas of South Chosen. Palaeontology. Part 3. Cambrian faunas Redlichiida). Beringeria 3: 1–363. of South Chosen with a special study on the Cambrian trilobite Geyer, G. 1990b. Revised Lower to lower Middle Cambrian genera and families. Journal of the Faculty of Science, Imperial biostratigraphy of Morocco. Newsletters on Stratigraphy 22(2/ University of Tokyo, Section II, 4:49–344. 3): 53–70. Kobayashi, T. 1943. Brief notes on the eodiscids I, their classification Geyer, G., and B. Buschmann. 2006. A new earliest Middle Cambian with a description of a new species and a new variety. faunule from Saxony (Germany) and its bearing on the Proceeding of the Imperial Academy Tokyo XIX 1: 37–42. tectonostratigraphic history of the Saxothuringian domain. In Kuhn, O., 1949. Lehrbuch der Palaözoologie. Stuttgart: Schweizerbart. South Australia 2006. XI International Conference of the Lapworth, C. 1888. On the discovery of the Olenellus fauna in the Cambrian Stage Subdivision Working Group, ed. Jago, J.B. Lower Cambrian rocks of Britain. Nature 39: 212–213. Geological Society of Australia, Abstracts Number 84:14–15. Latreille, P.A., 1829. Crustace´s, Arachnides et partie des Insectes. In: Geyer, G., and E. Landing. 2004. A unified Lower–Middle Cambrian Le Re`gne Animal, distribue´ d’apre`s son organisation, pour chronostratigraphy for west Gondwana. Acta Geologica Polo- servir de base a l’histoire naturelle des animaux et d’introduc- nica 54: 179–218. tion a` l’anatomie compare´, ed. G. Cuvier, Nouvelle e´dition, Geyer, G., and E. Landing. 2006. Ediacaran–Cambrian depositional revue et augmenteé. Tome IV: i–xxvii, 1–584. Paris. environments and stratigraphy of the western Atlas regions. In Lieberman, B.S. 2001. Phylogenetic Analysis of the Olenellina Morocco 2006 – Ediacaran–Cambrian depositional environ- Walcott, 1890 (Trilobita, Cambrian). Journal of Paleontology ments and stratigraphy of the western Atlas regions, eds. Geyer, 75(1): 96–115. G., and E. Landing. UCL Maghreb Petroleum Research Group, Linãn, E., and R. Gozalo. 1986. Trilobites del Ca´mbrico inferior y Infracambrian/Early Palaeozic Field Guide Series 1 and Berin- medio de Murero (Cordillera Ibe´rica). Memorias del Museo geria Special Issue 6:47–120. Paleontolo´gico, Universidad de Zaragoza 2: 1–104. 123 A new lowermost middle Cambrian 261

Linãń, E., and M. Mergl. 2001. Lower and Middle Cambrian Richter, R., and E. Richter. 1941. Das Kambrium am Toten Meer und brachiopods from the Iberian Chains and Sierra Morena, Spain. die a¨lteste Tethys. Abhandlungen der senckenbergischen naturf- Revista Espanõla de Paleontologıá 16(2): 317–337. orschenden Gesellschaft 460: 1–50. Linãń, E., M.E. Dies, J.A. Ga´mez Vintaned, R. Gozalo, and E. Richter, R., and E. Richter. 1948. Zur Frage des Unter-Kambriums in Mayoral. 2008. ‘‘Distinguishing eustatic and epeirogenic con- Nordost-Spanien. Senckenbergiana 29: 23–39. trols on Lower–Middle Cambrian boundary successions in West Rowell, A.J., 1965. Inarticulata. In Treatise On Invertebrate Paleon- Gondwana (Morocco and Iberia)’’, by Ed Landing, Gerd Geyer tology, Part H, Brachiopoda, ed. Moore, R.C.: H260–H296. and Wolfram Heldmaier, published in Sedimentology (2006), Boulder, CO: Geological Society of America, and Lawrence, 53(4), 899–918—discussion. Sedimentology 55:723–724. KS: University of Kansas Press. Linnarsson, G., 1877. Om faunan i lagren med Paradoxides œlandi- Rowell, A.J., 1966. Revision of some Cambrian and Ordovician cus. Sveriges geologiska Underso¨kning, Ser. C, 40, Fo¨reningen i inarticulate brachiopods. University of Kansas Paleontological Stockholm Fo¨rhandlingar 1877, III (12):352–375 [1–24]. Contributions, Paper 7. Linnemann, U., R. d’Lemos, K. Drost, T. Jeffries, A. Gerdes, R.L. Schmidt, E.W., 1944. Die mittelkambrische Fauna von Doberlug. Romer, S.D. Samson, and R.A. Strachan. 2008. Cadomian Jahrbuch der Reichsstelle fu¨r Bodenforschung 62 (for tectonics:103–154. In: The Geology of Central Europe, vol. 1. 1941):344–402. ed. T. McCann. London: The Geological Society. Schuchert, C. 1893. A classification of the Brachiopoda. The Lochman, C. 1956. Stratigraphy and paleogeography of the Ellipto- American Geologist 11: 141–167. cephala asaphoides strata in Cambridge and Hoosick quadran- Sdzuy, K. 1957a. Alter und tiergeographische Stellung des Mittel- gles, New York. Bulletin of the Geological Society of America kambriums von Doberlug. Geologie 6: 465–475. 67(10): 1331–1396. Sdzuy, K. 1957b. Revision der mittelkambrischen Trilobiten von Marek, L. 1963. New knowledge on the morphology of Hyolithes. Doberlug. Senckenbergiana Lethaea 38: 7–28. Sbornı´k geologickych veˇd, rˇada Paleontologie 1: 53–72. Sdzuy, K. 1958. Tiergeographie und Palaögeographie im europaïs- Matthew, G.F. 1887. Illustrations of the fauna of the St. John Group. chen Mittelkambrium. Geologische Rundschau 47: 450–461. No. 4.—on the smaller-eyed trilobites of Division I., with a few Sdzuy, K. 1962. Trilobiten aus dem Unter-Kambrium der Sierra remarks on the species of the higher divisions of the group. Morena (S-Spanien). Senckenbergiana Lethaea 43(3): 181–229. Canadian Record of Science 2: 357–363. Sdzuy, K. 1968. Trilobites del Ca´mbrico medio de Asturias. Trabajos Matthew, G.F. 1892. Protolenus—a new genus of Cambrian trilobites. de Geologıá, Facultad de Ciencias, Universidad de Oviedo 1: Bulletin of the Natural History Society of New Brunswick 10: 77–133. 34–37. Sdzuy, K. 1970. Mittelkambrische Fossilien aus neuen Bohrungen bei Matthew, G.F. 1893. Trematobolus. An articulate Brachiopod of the Doberlug und bei Delitzsch. Geologie 19: 1066–1091. Inarticulate Order. Canadian Record of Science 5: 276–279. Sdzuy, K., 1972. Das Kambrium der acadobaltischen Faunenpro- Matthew, G.F., 1895. The Protolenus Fauna. Transactions of the New vinz—Gegenwa¨rtiger Kenntnisstand und Probleme. Zentralblatt York Academy of Science XIV (for 1894–1895):101–153. fu¨r Geologie und Palaöntologie Teil II, Jg. 1972:1–91. Matthew, G.F. 1896. Notes on the Cambrian faunas—the genus Sdzuy, K., E. Linãń, and R. Gozalo. 1999. The Leonian Stage (early Microdiscus. American Geologist XVIII: 28–31. Middle Cambrian): a unit for Cambrian correlation in the Matthew, G.F., 1897. The oldest Siphonotreta. Geological Magazine, Mediterranean subprovince. Geological Magazine 136: 39–48. new series, Decade 4, IV:68–71. Sjo¨gren, A., 1872. Om na˚gra fo¨rsteningar i O¨ lands kambriska lager. Matthew, G.F., 1899. The Etcheminian Fauna of Smith Sound, Geologiska Fo¨reningen i Stockholm Fo¨rhandlingar 1 (5) (for Newfoundland. Transactions of the Royal Society of Canada 1872–1873):67–80. Series 2 V:97–123. Streng, M. 1999. Early Middle Cambrian representatives of the Mergl, M. 1988. Inarticulate brachiopods of early Middle Cambrian superfamily Acrotretoidea (Brachiopoda) from Morocco. Zeits- age from the High Atlas, Morocco. Vesˇtnı´k u´strˇenı´ho u´stavu chrift der deutschen geologischen Gesellschaft 150(1): 27–87. geologicke´ho 63(5): 291–295. Vogel, K., 1962. Muscheln mit Schloßza¨hnen aus dem spanischen Mergl, M., and O. Elicki. 2004. Cambrian lingulid and acrotretid Kambrium und ihre Bedeutung fu¨r die Evolution der Lamelli- brachiopods from the Iglesiente area (Campo Pisano Formation, branchiaten. Akademie der Wissenschaften und der Literatur, southwestern Sardinia). Rivista Italiana di Paleontologia i Mainz, Abhandlungen der mathematisch- naturwissenschaftli- Stratigrafia 110(3): 581–589. chen Klasse, Jg. 1962. No¨ldeke, W., 1976. Das Obervise´ von Doberlug–Kirchhain. Jahrbuch Walch, J.E.I., 1771. Die Naturgeschichte der Versteinerungen zur fu¨r Geologie 5/6 (for 1969/70):589–706. Erlaüterung der Knorrischen Sammlung von Merkwu¨rdigkeiten Palmer, A.R., and N.P. James. 1980. The Hawke Bay event: a circum- der Natur. Dritter Theil. [1–8], 1–235. Nu¨rnberg: Felßecker. Iapetus regression near the Lower–Middle Cambrian boundary. Walcott, C.D. 1908. Cambrian Geology and Paleontology, No. 3. In The Caledonides in the USA. ed. D.R. Wones, 15–18. Cambrian Brachiopoda: description of new genera and species. Department of Geological Sciences, Virginia Polytechnic Insti- Smithsonian Miscellaneous Collections LIII 3: 55–137. tute State Univ., Memoir 2. Walcott, C.D. 1910. Olenellus and other genera of the Mesonacidae. Popov, L.E., and L.E. Holmer. 2000. Family TREMATOBOLIDAE Smithsonian Miscellaneous Collections 53(6): 231–422. new family: 205–206. In Treatise on Invertebrate Paleontology. Westerga˚rd, A.H., 1936. Paradoxides oelandicus Beds of O¨ land with Part H. Brachiopoda, vol. 2. ed. Kaesler, R.L. Boulder, CO: the Account of a Diamond Boring through the Cambrian at Geological Society of America, and Lawrence, KS: University of Mo¨ssberga. Sveriges geologiska underso¨kning, Ser. C, 394, Kansas Press. A˚ rsb. 30 (f. 1936), 1. Rasetti, F. 1952. Revision of the North American trilobites of the Westrop, S.R., and E. Landing. 2000. Lower Cambrian (Branchian) family Eodiscidae. Journal of Paleontology 26(3): 434–451. trilobites and biostratigraphy of the Hanford Brook Formation, Raw, F. 1936. Mesonacidae of Comley in Shropshire, with a southern New Brunswick. Journal of Paleontology 74(5): 858–878. discussion of classification within the family. Quarterly Journal Williams, A., S. Carlson, C.H.C. Brunton, L.E. Holmer, and L.E. of the geological Society, London 92(3): 236–293. Popov. 1996. A supra-ordinal classification of the Brachiopoda. Richter, R., 1932. Crustacea (Palaöntologie) 840–863. In Handwo¨r- Philosophical Transactions of the Royal Society, London 351: terbuch der Naturwissenschaften, 2nd edn. Jena: Fischer. 1117–1193.

123 262 G. Geyer et al.

Wurm, A., 1925. U¨ ber ein Vorkommen von Mittelcambrium (Para- in stratigraphic correlation and biogeographic reconstructions. doxidesschichten) im bayrischen Frankenwald bei Wildenstein Geological Magazine 144(4): 661–686. su¨dlich Presseck. Neues Jahrbuch fu¨r Mineralogie etc., Beila- Zylin_ ´ska, A., and Z. Szczepanik. 2009. Trilobite and acritarch gen-Band 52, Abt. B:71–93. assemblages from the Lower–Middle Cambrian boundary inter- Zylin_ ´ska, A., and M. Masiak. 2007. Cambrian trilobites from val in the Holy Cross Mountains (Poland). Acta Geologica Brzecho´w, Holy Cross Mountains (Poland) and their signiﬁcance Polonica 59(4): 413–458.

123