Pala¨ontol Z (2012) 86:135–145 DOI 10.1007/s12542-011-0127-8
RESEARCH PAPER
Homeomorphy in Lunostoma, a new Middle Devonian cryptostome bryozoan Andrej Ernst • Paul D. Taylor • Jan Bohaty´ Patrick N. Wyse Jackson
•
Received: 1 February 2011 / Accepted: 7 December 2011 / Published online: 30 December 2011 Springer-Verlag 2011
Abstract A new genus and species of rhabdomesine cryptostome bryozoan, Lunostoma pulchra n. gen. n. sp., is described from the Lower Givetian (Middle Devonian) of the Eifel, Germany. It differs from all previously known rhabdomesines in having crescent-shaped structures (‘‘scuta’’) on the proximal sides of the apertures. These scuta resemble the lunaria that characterise cystoporate bryozoans, providing yet another example of homeomorphy in the Bryozoa. The function of scuta is unclear as, in contrast to lunaria, they do not project sufficiently from the apertures to constrain the everting lophophores. Keywords Devonian Bryozoa Taxonomy Homeomorphy Evolution Eifel (Rhenish Massif, Germany)
pulchra n. gen. n. sp. aus dem unteren Givetium (MittelDevon) der Eifel (Rheinisches Schiefergebirge, Deutschland) beschrieben. Morphologisch unterscheidet sie sich von allen bekannten Rhabdomesina durch halbmondfo¨rmige Strukturen (,,Scuta’’) an den proximalen Seiten der Aperturen. Diese Scuta a¨hneln frappant den fu¨r cystoporate Bryozoen charakteristischen Lunarien und liefern damit Beispiel fu¨r Homeomorphie bei pala¨ozoischen Bryozoen. Die Funktion der Scuta ist nicht klar, anders als bei Lunaria, da sie nicht weit genug aus den Aperturen hinausragen um die Ausstu¨lpung der Lophophoren einzuschra¨nken. Schlu¨sselwo¨rter Devon Bryozoa Taxonomie Homeomorphie Evolution Eifel (Rheinisches Schiefergebirge, Deutschland)
Kurzfassung Eine neue Gattung und Art einer rhabdomesinen cryptostomen Bryozoe wird als Lunostoma Introduction A. Ernst (&) Christian-Albrechts-Universita¨t zu Kiel, Institut fu¨r Geowissenschaften, Ludewig-Meyn-Str. 10, 24118 Kiel, Germany e-mail:
[email protected] P. D. Taylor Department of Palaeontology, Natural History Museum, Cromwell Road, London SW7 5BD, UK e-mail:
[email protected] J. Bohaty´ Universita¨t zu Ko¨ln, Institut fu¨r Geologie und Mineralogie, Zu¨lpicher Str. 49a, 50674 Ko¨ln, Germany e-mail:
[email protected] P. N. Wyse Jackson Department of Geology, Trinity College, Dublin 2, Ireland e-mail:
[email protected]
Cryptostome bryozoans are an important group of Palaeozoic Stenolaemata, displaying a long record from the Early Ordovician to the Late Permian (McKinney and Jackson 1989; Gorjunova 1996), although a recent report of a dubious rhabdomesine cryptostome bryozoan from the Late Cambrian of Mexico (Landing et al. 2010) may extend the range of the group. Cryptostomes are characterised by erect colonies in which usually short autozooecia bud in a more or less regular pattern so that their apertures are arranged in regular longitudinal or spiral rows, being shaped elliptical, subcircular or rectangular (Blake 1983). A characteristic feature of many cryptostome bryozoans is the development of different kinds of hemisepta, shelflike skeletal projections into the autozooecial chambers.
123
136
However, hemisepta can be found also in all other groups of Stenolaemata (notably in bifoliate cystoporates). Cystoporate bryozoans are another large group of Palaeozoic Stenolaemata which are characterised by encrusting, massive and diverse erect colonies. Cystoporates appeared in the Early Ordovician, and persisted apparently until the Late Triassic (Boardman 1984; Scha¨fer and Fois 1987). The most important cystoporate characters are long conical or tubular autozooecia, vesicular skeletons and lunaria (Utgaard 1983). The two latter characters do not necessarily occur in all genera. Whereas a vesicular skeleton is also known in some genera of Trepostomata and Cryptostomata (Ptilodictyina), lunaria seem to be unique to cystoporates, although a few examples of lunaria or lunarium-like structures are known in post-Palaeozoic cyclostomes (Borg 1965; Utgaard 1968). Lunaria represent hood-like projections over the autozooecial apertures and are absent in heterozooecia. In most genera, lunaria are radially arranged around maculae, located on the sides of zooecial apertures nearest to the macular centres. Lunarium-like structures were also mentioned in fenestrates (e.g. Schulga-Nesterenko 1941; Morozova 1970). However, these structures were subsequently revealed to be parts of sharply inclined vestibules (Morozova 2001). Therefore, fenestrates seem to lack any structures closely comparable to lunaria. Among Cryptostomata, lunaria have been described in two genera: Tavayzopora Kiseleva 1969 (Suborder Timanodictyina) and Junggarotrypa Lu 1999 (Suborder Ptilodictyina). Lunaria in Tavayzopora are small, semicircular projections in walls of autozooecial
Fig. 1 Map of Devonian bryozoan localities in the Rhenish Massif
123
A. Ernst et al.
chambers which are moderately calcified. This genus was described only from thin sections, so that it is impossible to determine whether these structures represent hood-like projections over the autozooecial apertures as in true lunaria. Junggarotrypa contains two species, but lunaria were described only in J. gratiosa, the type species. Lu (1999, p. 178) noted ‘‘lunaria distinct and semicircular in outline (…) and deeply indenting their strongly projected ends.’’ However, examination of the figures in his original publication fails to show any structural features that resemble lunaria in this genus. As a result this record of lunaria in ptilodictyinids cannot be confirmed. During a study of Devonian bryozoans of Europe, extensive material has been sampled and investigated. The locality of ‘‘Mu¨hlenwa¨ldchen’’ in SW-Gerolstein (Eifel, Rhenish Massif; Fig. 1) yielded many colonies of an undescribed rhabdomesine cryptostome bryozoan which contained structures resembling the lunaria of cystoporate bryozoans. This is the first report of such a morphological character in a cryptostome bryozoan. The present paper describes the new genus and species, and discusses its morphology and aspects of homeomorphy in bryozoans. Geological and palaeontological setting The lowermost Lower Givetian of the Gerolstein Syncline, from which the bryozoans described here were discovered, is dominated by sediments which clearly differ from the Type Eifelian at the reference profile within the Hillesheim Syncline (Struve 1982; Struve and Werner 1982). Therefore,
Homeomorphy in Lunostoma
137
Fig. 2 Lowermost Lower Givetian stratigraphy of the ‘‘Type Eifelian Profile’’ sensu Struve (1982) (a), and comparison with the regional members of the Cu¨rten and Loogh Formations (grey) within the Gerolstein SW and NE facies (after Winter 1965) (b)
several local members of the Loogh and Cu¨rten Formations were established by Winter (1965) (Fig. 2), who also differentiated between Gerolstein south-western and northeastern regional facies. The studied bryozoans come from the Lower Givetian Loogh Formation (hemiansatus Conodont Biozone) of the south-western part of the Gerolstein Syncline. Regionally, the base of the Loogh Formation (Fig. 2) consists of the Dachsberg Member comprising homogeneous limestones containing sparsely preserved macrofossils (Winter 1965). According to Winter (1965, p. 289), the Dachsberg Member is restricted to the southwest of the Gerolstein Syncline. These limestones were deposited under quiet conditions (Winter 1965, p. 307). Progressive shallowing led to the inception of biostromal growth and facies differentiation characterising the Baarley Member of Winter (1965, pp. 289–290). Massive trochite-dominated limestones and ‘‘matrix limestones’’ characterise this member. Local facies differences within the Baarley Member often modify this basic lithology. The bryozoan locality ‘‘Mu¨hlenwa¨ldchen’’ (Fig. 1) is characterised by both fine-grained homogeneous limestone and marl banks. More regular limestone–marl interbeds increase towards the boundary of the overlying Hustley Member (Winter 1965, pp. 290–292), which represents a temporary decrease in sedimentation marked by the appearance of stromatoporoid/coral biostromes. These biostromes, with partly limy, partly marly deposits, mark the maximum level of facies differentiation. The ‘‘Mu¨hlenwa¨ldchen’’ site in the SW-Gerolstein (Gerolstein Syncline, Eifel, Rhenish Massif, north-western Rhineland-Palatinate, Germany) is located at UTM 50130 16.14’’N, 6390 01.00’’E (Fig. 1). Stratigraphically,
the bryozoan outcrop is presumably positioned within the lower Baarley Member [regional valid denomination of the uppermost Wotan Member (Hotz et al. 1955) of the Gerolstein Syncline (sensu Winter 1965)] of the middle Loogh Formation, Lower Givetian (Middle Devonian; hemiansatus Conodont Biozone). This historic fossil locality is most famous for well-preserved crinoid cups (comprising melocrinititids, rhodocrinitids, megaradialocrinitids and hexacrinitids, as reported by Bohaty´ 2006, p. 472), echinoids, brachiopods, rugose and tabulate corals (e.g. Bohaty´ et al. in press), platyceratid gastropods, phacopid trilobites, cyclostome, trepostome, as well as a diverse spectrum of fenestrate bryozoans. The latter include the aberrant semicosciniid Schischcatella heinorum Ernst and Bohaty´ 2009 typically found attached to mimatrypid brachiopods or, rarely, to crinoid pluricolumnals.
Material and methods Colonies of Lunostoma pulchra n. gen. n. sp. were studied in thin sections and with scanning electron microscopy (SEM). Thin sections were made directly from hand specimens and also from colonies embedded in SpeciFix-40 epoxy resin. Morphological terminology is modified from Hageman (1993). The following morphological characters were measured: width of branch, width of endozone, aperture width, distance between aperture centres along branch, distance between aperture centres across branch, length of scutum, width of scutum, thickness of scutum, diameter of aktinotostyles and spacing of hemiphragms (Fig. 3; Table 1).
123
138
A. Ernst et al.
Fig. 3 Overview of morphology of Lunostoma pulchra n. gen. n. sp. and important measurements (see text for explanation)
Table 1 Lunostoma pulchra n. gen. n. sp. (Middle Devonian, Rhenish Massif) N
X
SD
CV
MIN
MAX
WB
13
1.29
0.303
23.42
0.96
1.82
EW
6
0.82
0.267
32.71
0.60
1.20
AW
45
0.12
0.014
11.76
0.10
0.14
ADB
45
0.55
0.077
14.03
0.37
0.69
AAB
45
0.29
0.030
10.14
0.24
0.37
SL
17
0.06
0.010
15.28
0.05
0.08
SW ST
17 4
0.06 0.04
0.013 0.004
22.43 11.66
0.04 0.03
0.08 0.04
AD
30
0.03
0.010
28.33
0.02
0.06
HS
30
0.10
0.016
17.17
0.08
0.13
Systematic palaeontology Phylum Bryozoa Ehrenberg 1831 Class Stenolaemata Borg 1926 Order Cryptostomata Vine 1884 Suborder Rhabdomesina Astrova and Morozova 1956 Family Rhomboporidae Simpson 1895 Genus Lunostoma n. gen. Type species monotypy.
Lunostoma pulchra n. gen. n. sp., by
Derivation of name The genus name refers to the presence of crescent-shaped partitions in the apertures (from Latin Luna = moon, and Greek stoma = mouth, opening).
Summary descriptive statistics (measurements in mm) of 13 colonies Statistics—number of measurements (N), arithmetic mean (X), sample standard deviation (SD), coefficient of variation (CV), and minimum (MIN) and maximum (MAX) values; morphologic characters—WB (width of branch), WE (width of endozone), AW (aperture width), ADB (distance between aperture centres along branch), AAB (distance between aperture centres across branch), SL (length of scutum), SW (width of scutum), ST (thickness of scutum), AD (diameter of aktinotostyles), HS (spacing of hemiphragms)
Studied material is housed at the Senckenberg Museum (Frankfurt am Main, Germany). Five colonies, numbered SMF 20.927–SMF 20.929, were studied using SEM at the Institute of Geosciences, University of Kiel (CAMSCANSerie-2-CS-44). Thin sections were prepared from 12 colonies (SMF 20.915–SMF 20.926).
123
Diagnosis Colonies branched, arising from basal discs. New branches arising at angle of 90 from the older branches. Axial region formed by well-defined median axis. Autozooecia moderately long, initially polygonal, budding in spiral order at angles of 19–23 from the median axis in endozones, then bending gently and intersecting the colony surface at angles of 60–63. Autozooecial apertures arranged rhombically. Distally curved multiple hemisepta occurring on the distal autozooecial wall. Diaphragms rare to absent. Aktinotostyles abundant, Fig. 4 Lunostoma pulchra n. gen. n. sp. All specimens from the c Middle Devonian (Lower Givetian) of the Rhenish Massif, northwestern Rhineland-Palatinate, Germany. a Paratype SMF 20.928, general view of a colony. b, c Paratype SMF 20.928, colony surface showing apertures with scuta and paurostyles. d, e Paratype SMF 20.929, colony surface showing apertures with scuta and paurostyles
Homeomorphy in Lunostoma
139
123
140
123
A. Ernst et al.
Homeomorphy in Lunostoma b Fig. 5 Lunostoma pulchra n. gen. n. sp. All specimens from the Middle Devonian (Lower Givetian) of the Rhenish Massif, northwestern Rhineland-Palatinate, Germany. a Paratype SMF 20.917, branch longitudinal section showing autozooecia with multiple hemisepta. b, c Paratype SMF 20.924, branch longitudinal section showing autozooecia with multiple hemisepta and wall structure. d, e Paratype SMF 20.920, branch transverse section showing axial region and shape of autozooecia in endozone. f–h Holotype SMF 20.916, tangential section showing autozooecial apertures, scuta and aktinotostyles
spaced regularly between autozooecial apertures, locally forming small clusters. Autozooecial walls finally laminated, with median dividing layer in endozone; coarsely laminated, thickened in exozones. Scuta present, positioned on proximal ends of autozooecial apertures, directed toward colony base. Comparison Lunostoma n. gen. differs from all other rhabdomesine cryptostomes in having apertural partitions (herein called scuta) and in the distally curved multiple hemisepta. The new genus is similar to Saffordotaxis Bassler 1952 in both the presence and distribution of aktinotostyles and the shape of the autozooecia. Occurrence and geological age Lower Givetian (Middle Devonian) of the Rhenish Massif, Germany. Lunostoma pulchra n. gen. n. sp. Figures 3–6 Derivation of name The species name derives from Latin pulchra = beautiful. Holotype
SMF 20.916.
Paratypes Fourteen colonies SMF 20.915, SMF 20.917– SMF 20.926 (thin sections), SMF 20.927–SMF 20.929 (SEM samples). Locus typicus ‘‘Mu¨hlenwa¨ldchen’’, SW-Gerolstein, Gerolstein Syncline, Eifel, Rhenish Massif, Germany; UTM: 50130 16.28’’N, 6390 02.28’’E. Stratum typicum Lower Baarley Member of the middle Loogh Formation, Lower Givetian, Middle Devonian; hemiansatus Conodont Biozone. Diagnosis
As for genus.
Description Colonies branched, growing from basal discs, branches 0.96–1.82 mm in diameter, with 0.60– 1.20 mm wide endozones and 0.18–0.31 mm wide exozones. Axial region formed by well-defined median axis. Autozooecia moderately long, initially polygonal, budding in spiral order at angles of 19–23 from the median axis in endozones, then bending gently and intersecting the colony surface at angles of 60–63. Autozooecial apertures oval, arranged rhombically in longitudinal rows on colony
141
surface. Long multiple hemisepta occurring on the distal autozooecial wall throughout autozooecial chamber, distally curved, closely spaced. Diaphragms rare to absent. Aktinotostyles moderately large, abundant, spaced regularly between autozooecial apertures in 1–2 rows, locally forming small clusters, originating at the base of exozone. Autozooecial walls finally laminated, with median dividing layer, 0.015–0.035 mm thick in endozone; coarsely laminated, thickened in exozones. Scuta present, horseshoe shaped, positioned on the proximal edge of autozooecial apertures. Comparison
As for genus.
Discussion Scutum: a new zooecial structure and its function In Lunostoma, horseshoe-shaped skeletal shields—here termed ‘‘scuta’’—are situated on the proximal edge of autozooecial apertures and positioned suborally, i.e. below the level of the exterior surface of the aperture. In plan view, scuta are similar in shape to the lunaria present in most cystoporate bryozoans (Utgaard 1983). However, cystoporate lunaria differ from scuta in that they usually extend into a hood-like structure that projects over the autozooecial aperture above the colony surface. The scuta of Lunostoma do not appear to be the abraded bases of true lunaria, but rather are crescent-shaped suboral shields, hence the name ‘‘scutum’’ (plural ‘‘scuta’’) from the Latin for the semi-cylindrical shields carried by Roman legionaries. Whereas projecting, hood-like lunaria may have functioned in directing the lophophore distally, the function of scuta is unclear. They resemble the poster of ascophoran cheilostome bryozoans, i.e. the part of the orifice proximal of the opercular condyles and leading to the ascus or compensation sac involved in lophophore eversion (Hayward and Ryland 1979). However, stenolaemates including Lunostoma lack an ascus. Furthermore, it is improbable that Lunostoma possessed an operculum: opercula are absent in all but a few stenolaemates (cf. eleid cyclostomes, see Taylor 1985) and apparently require exterior wall on which to hinge whereas the skeleton of Lunostoma comprises interior wall only. Homeomorphy in stenolaemate bryozoans The development of scuta in these Devonian cryptostomes is another example of homeomorphy in bryozoans. This term was first coined by Buckman (1895) (Afanas’yeva 1977), who realised that similar or identical morphological characters could be recognised in different taxa that may or
123
142
123
A. Ernst et al.
Homeomorphy in Lunostoma b Fig. 6 Lunostoma pulchra n. gen. n. sp. All specimens from the Middle Devonian (Lower Givetian) of the Rhenish Massif, northwestern Rhineland-Palatinate, Germany. a Paratype SMF 20.916, tangential section showing autozooecial apertures, scuta and aktinotostyles. b, c Paratype SMF 20.924, branch longitudinal section showing autozooecia with hemiphragms and wall structure. d Paratype SMF 20.917, branch longitudinal section showing autozooecia with hemiphragms and wall structure. e Paratype SMF 20.925, tangential section showing aktinotostyles. f–h Paratype SMF 20.917, branch longitudinal section showing aktinotostyles in exozone
may not be separated by time. Homeomorphy is a result of convergent evolution of traits (homoplasy), sometimes through heterochrony (Anstey 1987). Homeomorphy has been described in brachiopods (Cloud 1941), cephalopods (Reyment 1955; Evans 2007) and echinoderms (Blake and Kues 2002) amongst other groups, and is frequent in bryozoans (e.g. Voigt and Flor 1970; Hinds 1975; Blake 1980; McKinney et al. 1993; Taylor and Badve 1995). Both colonial- and zooidal-level homeomorphy can be found in bryozoans; for example, colonies with distinctive lyre-shaped colonies occur in the fenestrate genera Lyropora and Lyroporella from the Mississippian of North America and are also found in a cyclostome species from the Eocene Castle Hayne Limestone Formation of North Carolina (McKinney et al. 1993). Similarly, the development of a spiral axis in the Mississippian fenestrate Archimedes and the Eocene cyclostome Crisidmonea (Taylor and McKinney 1996) represents homeomorphy at colonial level. McKinney et al. (1993) cited additional examples of homeomorphy in bryozoan morphology that involve branch development (Blake 1980) and surface topography (Winston 1979). At zooidal level, Hageman (1991) noted
Fig. 7 Fistuliphragma eifelensis Ernst 2008. Nims Member of the Upper Junkerberg Formation (Eifelian, Middle Devonian) of Gondelsheim, Pru¨m Syncline, Eifel (western Rhenish Massif, Germany).
143
homeomorphy in the Carboniferous cryptostome Worthenopora with zooids superficially resembling those of some post-Palaeozoic cheilostomes. More remarkable is the homeomorphy between Cretaceous–Paleocene melicerititid cyclostomes and cheilostomes, the former being highly unusual among cyclostomes in possessing cheilostome-like opercula to close the aperture and developing polymorphic zooids with enlarge opercula that resemble cheilostome avicularia (Taylor 1985). The long, horn-shaped zooids of the Cretaceous cheilostome Chiplonkarina are strongly homeomorphic with stenolaemates, such as the cyclostome Ceriocava (Taylor and Badve 1995). Homeomorphy of internal characters in stenolaemate bryozoans includes the development of four-sided autozooecial chambers in trepostome bryozoans, which arose independently at least four times between the Ordovician and the Permian (Boardman and McKinney 1976). The extent to which homeomorphy compromises stenolaemate bryozoan taxonomy is contestable. Boardman (1984), in a discussion of the origins of the post-Triassic stenolaemates, believed that some post-Palaeozoic cyclostomes sharing morphological traits with Palaeozoic stenolaemates were direct descendants of these supposedly extinct taxa rather than their homeomorphs. In contrast, molecular sequence data obtained from Recent cyclostomes has shown numerous skeletal morphological characters to represent homoplasy (Waeschenbach et al. 2009), implying high levels of homeomorphy among stenolaemates. The new rhabdomesine genus Lunostoma provides another example of homeomorphy at the zooidal level. Scuta, proximally placed skeletal partitions in the autozooecial apertures of Lunostoma, strongly resemble the
a SMF 2735, colony surface with autozooecial apertures. (SEM). b SMF 2730, tangential section displaying autozooecial aperture
123
144
lunaria that characterise cystoporate bryozoans (Fig. 7). Lunarium-like structures have also been described, for example, from the Cretaceous cyclostome Lunariopsis by Voigt (1993). There can be little doubt that the scuta of Lunostoma and the lunaria of cystoporates are nonhomologous given that rhabdomesines are distantly related to cystoporates. However, as with other cases of homeomorphy in bryozoans, a more robust phylogenetic framework than that which is presently available is required. Only then will the true extent of homeomorphy across the phylum become fully apparent. Phylogenetic position of Lunostoma Lunostoma in its general morphology is close to the rhabdomesine Family Rhomboporidae Simpson, 1895. Shared characters are: rhombic arrangement of apertures, budding of autozooecia from a distinct median axis, autozooecial shape and orientation, and presence of aktinotostyles (Blake 1983: 576). However, Lunostoma possesses two cardinal characters which do not occur in the Suborder Rhabdomesina: scuta and distally curved multiple hemisepta. Both these morphologies are apparently unique among Bryozoa (see also previous discussion). Rhomboporids usually lack hemisepta, which are normally superimposed superior and inferior hemisepta, or have only one type. Rarely, multiple hemisepta occur in rhabdomesines, but these are proximally curved structures on the proximal wall like those in some species of the rhabdomesid genus Ascopora (Blake 1983: 571). The most similar genus to Lunostoma appears to be Saffordotaxis Bassler 1952 of the Family Rhomboporidae. Acknowledgments We thank Wolfgang Reimers (Kiel) for his assistance in preparing the thin sections, and Ute Schuldt (Kiel) for help with SEM processing. Robert Anstey, East Lansing and Kamil Za´gorsˇek, Prague, are thanked for their helpful and constructive reviews of the manuscript. Most of the studied bryozoan material was collected during the crinoid research project of the Deutsche Forschungsgemeinschaft (DFG project HE1610/16-1); J.B. gratefully acknowledged the financial support. Also A.E. thanks the Deutsche Forschungsgemeinschaft for financial support (DFG project ER 278/4.1 and 2). This paper is a contribution to IGCP 499.
References Afanas’yeva, G.A. 1977. The term ‘‘homeomorphy’’. Paleontologicheskiy Zhurnal 11: 505–507. Anstey, R.L. 1987. Astogeny and phylogeny: evolutionary heterochrony in Paleozoic bryozoans. Paleobiology 13: 20–43. Astrova, A.A., and I.P. Morozova. 1956. About systematics of the Order Cryptostomata. Doklady Akademii Nauk SSSR 110(4): 661–664. Bassler, R.S. 1952. Taxonomic notes on genera of fossil and Recent Bryozoa. Journal of the Washington Academy of Science 42: 381–385.
123
A. Ernst et al. Blake, D.B. 1980. Homeomorphy in Paleozoic bryozoans: a search for explanations. Paleobiology 6: 451–465. Blake, D.B. 1983. The order cryptostomata. In Treatise on invertebrate paleontology. (Part G) Bryozoa—revised, vol. 1, ed. R.A. Robison. Boulder and Lawrence: Geological Society of America and University of Kansas. Blake, D.B., and B.S. Kues. 2002. Homeomorphy in the Asteroidea (Echinodermata): a new Late Cretaceous genus and species from Colorado. Journal of Paleontology 76: 1007–1013. Boardman, R.S. 1984. Origin of the Post-Triassic Stenolaemata (Bryozoa): a taxonomic oversight. Journal of Paleontology 58: 19–39. Boardman, R.S., and F.K. McKinney. 1976. Skeletal architecture and preserved organs of four-sided zooids in convergent genera of Paleozoic Trepostomata (Bryozoa). Journal of Paleontology 50: 25–78. ¨ ber den taxonomischen Status des mitteldevonisBohaty´, J. 2006. U chen Hexacrinites crispus (Quenstedt, 1861) [Crinoidea, Camerata] aus dem linksrheinischen Schiefergebirge Deutschlands. Neues Jahrbuch fu¨r Geologie und Pala¨ontologie—Monatshefte, 2006(8): 471–482. Bohaty´, J., Ausich, W.I., Nardin, E., Nyhuis, C., and Schro¨der, S. (in press). Coral-crinoid biocoenosis and resulting trace fossils from the Middle Devonian of the Eifel Synclines (Rhenish Massif, Germany). Journal of Paleontology. Borg, F. 1926. Studies on recent cyclostomatous Bryozoa. Zoologiska Bidrag fran Uppsala 10: 181–507. Borg, F. 1965. A comparative and phyletic study on fossil and recent Bryozoa of the suborders Cyclostomata and Trepostomata. Arkiv fo¨r zoologi Bd 17: 1–91. Buckman, S.S. 1895. The Bajocian of the mid-Cotteswolds. Quarterly Journal of the Geological Society of London 51: 445–458. Cloud, P.E. 1941. Homeomorphy, and a remarkable illustration. American Journal of Science 239: 899–904. Ehrenberg, C.G. 1831. Symbolae Physicae, seu Icones et descptiones Corporum Naturalium novorum aut minus cognitorum, quae ex itineribus per Libyam, Aegiptum, Nubiam, Dongalaam, Syriam, Arabiam et Habessiniam, studia annis 1820–1825, redirent. Pars. Zoologica, 4, Animalia Evertebrata exclusis Insectis. Berolini, 10 pls. Ernst, A. 2008. Non-fenestrate bryozoans from the Middle Devonian of the Eifel (western Rhenish Massif, Germany). Neues Jahrbuch fu¨r Geologie und Pala¨ontologie, Abhandlungen 250(3): 313–379. Ernst, A., and J. Bohaty´. 2009. Schischcatella (Fenestrata, Bryozoa) from the Devonian of the Rhenish Massif, Germany. Palaeontology 52(6): 1291–1310. Evans, D.H. 2007. A Middle Ordovician cephalopod fauna from Cuzco Province, southern Peru and its palaeobiogeographical significance. Geological Journal 42: 25–36. Gorjunova, R.V. 1996. Phylogeny of the Paleozoic Bryozoa morphology and system of the Paleozoic bryozoans. Trudy Paleontologischeskogo Instituta Rossijskoj Akademii Nauk 267: 1–161. Hageman, S.J. 1993. Effects of nonnormality on studies of the morphological variation of a rhabdomesine Bryozoan, Streblotrypa (Streblascopora) prisca (Gabb Horn). The University of Kansas Paleontological Contributions 4: 1–13. Hageman, S.J. 1991. Worthenopora; an unusual cryptostome (Bryozoa) that looks like a cheilostome. Journal of Paleontology 65: 648–661. Hayward, P.J. and Ryland, J.S. 1979. British Ascophoran Bryozoans. Academic Press, London, pp. v ? 312. Hinds, R.W. 1975. Growth mode and homeomorphism in cyclostome Bryozoa. Journal of Paleontology 49: 875–910. Hotz, E.E., Kra¨usel, W. and Struve, W. 1955. Die Kalkmulden von Hillesheim und Ahrdorf. In Kro¨mmelbein, K., Hotz, E. E.,
Homeomorphy in Lunostoma Kra¨usel, W. and Struve, W.: Zur Geologie der Eifelkalkmulden. Beiheft Geologisches Jahrbuch 17: 45–192. Landing, E., A. English, and J.D. Keppie. 2010. Cambrian origin of all skeletalized metazoan phyla—Discovery of Earth’s oldest bryozoans (Upper Cambrian, Southern Mexico). Geology 38: 547–550. Kiseleva, A.V. 1969. New bryozoans of the family Girtyporidae the Upper Permian of the Southern maritime territory. Paleontological Journal 1: 79–84. Lu, L. 1999. Famennian-Tournaisian bryozoans of the Aergati Mt., NW Xinjiang. In Palaeozoic fossils of northern Xinjiang, China, 37–47, 142–186. Nanjing Institute of Geology and Palaeontology, Academia Sinica, Nanjing. McKinney, F.K., and J.B.C. Jackson. 1989. Bryozoan Evolution. Boston: Unwin Hyman. McKinney, F.K., P.D. Taylor, and V.A. Zullo. 1993. Lyre-shaped hornerid bryozoan colonies: homeomorphy in colony form between Paleozoic Fenestrata and Cenozoic Cyclostomata. Journal of Paleontology 67: 343–354. Morozova, I.P. 1970. Late Permian Bryozoa. Trudy Paleontologicheskogo Instituta Akademii Nauk SSSR 122: 1–347. Morozova, I.P. 2001. Bryozoans of the Order Fenestellida. Trudy Paleontologicheskogo Instituta Rossijskoj Akademii Nauk 277: 1–176. Reyment, R. 1955. Some examples of homeomorphy in Nigerian Cretaceous ammonites. Geologiska Fo¨reningens i Stockholm Fo¨rhandlingar 77: 567–594. Scha¨fer, P., and E. Fois. 1987. Systematics and evolution of Triassic Bryozoa. Geologica et Paleontologica 21: 173–225. Schulga-Nesterenko, M.I. 1941. Lower Permian Bryozoa of Urals. Paleontology of the USSR 5: 1–276. Simpson, G.B. 1895. A handbook of the genera of the North American Paleozoic Bryozoa. 14th Annual Report of the State Geologist (of New York) for the year 1894, pp. 407–608. Struve, W. 1982. The Eifelian within the Devonian frame, history, boundaries, definitions. In On Devonian Stratigraphy and Palaeontology of the Ardenno-Rhenish Mountains and related Devonian Matters, W. Ziegler and R. Werner, Courier Forschungsinstitut Senckenberg 55: 401–432. Struve, W. and Werner, R. 1982. The lower/middle Devonian boundary and the Eifelian stage in the ‘‘Type Eifelian’’ region. In Field meeting on Lower and Lower Middle Devonian stages in
145 the Ardenno-Rhenish type area, guidebook, eds G. Plodowski, R. Werner and W. Ziegler, 81–151, figs. 1–6, 2 maps (1:10.000); Frankfurt am Main. Taylor, P.D. 1985. Polymorphism in melicerititid cyclostomes. In Ordovician to Recent eds. Nielsen, C. and Larwood, G. P. Bryozoa. pp. 311–318, Fredensborg: Olsen and Olsen. Taylor, P.D., and R.M. Badve. 1995. A new cheilostome bryozoan from the Cretaceous of India and Europe: a cyclostome homeomorph. Palaeontology 38: 627–657. Taylor, P.D., and F.K. McKinney. 1996. An Archimedes-like cyclostome bryozoan from the Eocene of North Carolina. Journal of Paleontology 70: 218–229. Utgaard, J. 1968. A revision of North American genera of ceramoporoid bryozoans (Ectoprocta): Part I; Anolotichiidae. Journal of Paleontology 42: 1033–1041. Utgaard, J.E. 1983. Paleobiology and Taxonomy of the Order Cystoporata. In Treatise on Invertebrate Paleontology. (Part G) Bryozoa—Revised, vol. 1, ed. R.A. Robison, 327–439. Boulder and Lawrence: Geological Society of America and University of Kansas. Vine G.R. 1884. Fourth report of the committee consisting of Dr. H. R. Sorby and Mr. G. R. Vine, appointed for the purpose of reporting on fossil Polyzoa. Reports of the 53rd Meeting of the British Association for the Advancement in Sciences, 161–209. Voigt, E. 1993. Zwei neue Bryozoen-Genera (Cyclostomata) aus dem westfa¨lischen Cenoman. Zitteliana 20: 361–368. Voigt, E., and F.D. Flor. 1970. Homoeomorphien bei fossilen cyclostomen Bryozoen, dargestellt am Beispiel der Gattung Spiropora Lamouroux 1821. Mitteilungen aus dem GeologischPalaeontologischen Institut der Universita¨t Hamburg 39: 7–96. Waeschenbach, A., C.C. Cox, D.T.J. Littlewood, J.S. Porter, and P.D. Taylor. 2009. First molecular estimate of cyclostome bryozoan phylogeny confirms extensive homoplasy among skeletal characters used in traditional taxonomy. Molecular Phylogenetics and Evolution 52(1): 241–251. Winston, J.E. 1979. Current-related morphology and behaviour in some Pacific coast bryozoans, pp. In Advances in Bryozoology, ed. G.P. Larwood, and M.B. Abbott, 247–286. London: Academic Press. Winter, J. 1965. Das Givetium der Gerolsteiner Mulde (Eifel). Fortschritte in der Geologie von Rheinland und Westfalen 9: 277–322.
123
