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Thylacocephala are among the most problematic of arthropod fossils. Various authors have allied them with all manner of crustacean groups, including branchiopods, cirripedes, remipedes, and malacostracans. They have a very apomorphic body plan often marked by hypertrophy of the compound eyes, three pairs of large raptorial subchelate limbs, eight sets of well-developed phyllobranch gills, and from 8 to at least 16 posterior trunk somites bearing paddle-like limbs. They have been thought of as a distinct class composed of two orders, Concavicarida and Conchyliocarida, but membership within the orders varies according to authors, and no familial divisions have been proposed within the orders until now. This lack of taxonomic structure inhibits organization of available information concerning the paleoecology, paleogeography, and phylogenetic relationships of thylacocephalans. A working hypothesis for the higher taxonomy within the class is proposed here. This entails a redefinition of the two orders, and recognition of seven families, five of them new: Austriocarididae Glaessner, 1931, Clausocarididae Arduini, 1992 (new status), Concavicarididae n. fam., Dollocarididae, n. fam., Microcarididae n. fam., Ostenocarididae n. fam. and Protozoeidae n. fam.

We performed a phylogenetic analysis of the crustacean class Remipedia. For this purpose, we generated sequences of three different molecular markers, 16S rRNA (16S), histone 3 (H3), and cytochrome c oxidase subunit I (COI). The analyses included sequences from 20 of the 27 recent species of Remipedia, plus four still-undescribed species. The data matrix was complemented with sequences from online databases (The European Molecular Biology Laboratory and GenBank®). Campodea tillyardi (Diplura), Hutchinsoniella macracantha (Cephalocarida), Penaeus monodon (Malacostraca) and Branchinella occidentalis (Branchiopoda) served as out-groups. In addition to the classic computer-based alignment methods used for protein-coding markers (H3 and COI), an alternative approach combining structural alignment and manual optimization was used for 16S. The results of our analyses uncovered several inconsistencies with the current taxonomic classification of Remipedia. Godzilliidae and the genera Speleonectes and Lasionectes are polyphyletic, while Speleonectidae emerges as a paraphyletic group. We discuss current taxonomic diagnoses based on morphologic characters, and suggest a taxonomic revision that accords with the topologies of the phylogenetic analyses. Three new families (Kumongidae, Pleomothridae, and Cryptocorynetidae) as well as three new genera (Kumonga, Angirasu, and Xibalbanus) are erected. The family Morlockiidae and the genus Morlockia are removed from synonymy and returned to separate status.

Cancer is one of the “oldest” names in carcinology, but like many old and familiar things it has fallen into use as a catch-all category, especially by non-taxonomists. Much taxonomic revision has occurred in Brachyura: Cancridae [Cancer] in recent years, and unfortunately, much of it has passed completely under the radar of biologists. A summary of that revisionary work is provided along with a list of currently accepted names for the living species of Cancridae. We offer this contribution in an effort to cut off the use of old, and in many cases invalid, binomina, and to encourage the use of a modern, up-to-date classification of cancrid crabs.

As a result of cladistic analyses involving fossil hoplocaridans, the palaeostomatopods emerge as paraphyletic. Consequently, the genus Archaeocaris requires a separate family, erected herein. A partir des resultats d'analyses cladistiques incluant les formes hoplocarides fossiles, les palaeostomatopodes emergent comme paraphyletiques. En consequence le genre Archaeocaris necessite la creation d'une famille separee, ce que nous faisonsici.

A cladistic analysis based on external morphology was carried out on 60 taxa of decapod crustaceans. An analysis with unordered characters and one with ordered characters were both in agreement regarding the major relationships. The ordered analysis gave better resolution of more advanced clades, while the unordered analysis gave better resolution of more basal clades. None of the traditional groups Palinura, Anomura, and Macrura is monophyletic. A new classie cation of decapod crustaceans is proposed. Homarida and Astacida are closely related, as shown by the unique process on the ischium of their e rst pereiopods. Glypheoidea forms the sister group to Astacura, within an enlarged Astacidea. Achelata is the sister group to Meiura (Anomala + Brachyura) in a new clade, Eurysternalia, characterized by a unique antennular morphology and by the eponymous wide sternum of its members. Thalassinida emerge as the sister group to Eurysternalia, in a new clade, Sterropoda, characterized by fusion of the e rst segments of the thoracic limbs. The fractostern is interpreted to be a eureptant feature, and a possible burrowing habitus is posited for the ancestral Eureptantia.

[A new genus and species of fossil decapod, Jilinocaris chinensis, is described from the Late Cretaceous of northern China. Although incompletely preserved, enough anatomy is visible to suggest that this species represents the first fossil example of the Stenopodidea and is tentatively assigned to the family Spongicolidae. Es wird eine neue Gattung und Art eines fossilen Dekapoden, Jilinocaris chinensis, aus der Unterkreide Nordchinas beschrieben. Obwohl nicht vollstandig erhalten, reichen die auswertbaren anatomischen Daten aus, um diese Art als erstes fossiles Exemplar der Stenopodidea vorzuschlagen und vorerst der Familie Spongicolidae zuzuordnen., A new genus and species of fossil decapod, Jilinocaris chinensis, is described from the Late Cretaceous of northern China. Although incompletely preserved, enough anatomy is visible to suggest that this species represents the first fossil example of the Stenopodidea and is tentatively assigned to the family Spongicolidae. Es wird eine neue Gattung und Art eines fossilen Dekapoden, Jilinocaris chinensis, aus der Unterkreide Nordchinas beschrieben. Obwohl nicht vollstandig erhalten, reichen die auswertbaren anatomischen Daten aus, um diese Art als erstes fossiles Exemplar der Stenopodidea vorzuschlagen und vorerst der Familie Spongicolidae zuzuordnen.]

A new subterranean amphipod species, Bogidiella (Medigidiella) arista, found in the mesopsammic ground waters of southern Anatolia, Turkey, is described, together with Bogidiella (Bogidiella) calicali Karaman, the latter being recorded for the first time in the eastern Mediterranean. A cladistic analysis of 37 Mediterranean species of the family Bogidiellidae is performed, using 4 species from the Canary Islands as an outgroup. Alternatively, 2 cladistic software packages, PAUP 3.1.1 and HENNIG86, are employed to calculate consensus trees of minimal length. The resulting trees show more or less identical robust clades, characterizing a central, a central-eastern, and an eastern Mediterranean group. Apart from this pattern of major geographical clusters, all species of the subgenus Medigidiella appear as a robust, monophyletic clade as well. This initial attempt to analyze the phylogeny of Mediterranean bogidiellids forms a useful basis for further, extended studies, using either different outgroup taxa or additional morphological data. During the spring of 1987 a major biospeleological expedition of the Dutch speleological society "Speleo Nederland" was carried out along the coastal Taurus mountains in southwest Anatolia, Turkey. The expedition was focused on collecting the fauna of caves, wells, subterranean water flows, and the interstices of marine gravel beaches. The special yield of subterranean (or stygobiont) crustaceans, predominantly amphipods of the genus Bogidiella Hertzog, 1933, promised to serve as an interesting case study to the colonization of inland ground water by marine organisms. In July 1996, a second sampling program occurred along the southern Turkish coast between Antalya and Alanya. Its main objectives were, first, to visit one or two Speleo Nederland stations and enlarge the small original sample sizes (1-3 individuals), and, second, to collect a new series of samples east of where the 1987 expedition went, in order to obtain additional distribution data about stygobiont crustaceans. Unfortunately, the first task could not be achieved. In contrast to Speleo Nederland, the 1996 sampling program took place in the dry season when the ground-water level was low and many minor streams and rivers had become partly or completely dry. This, combined with the fact that many bogidiellids seem to have extremely limited distribution ranges with low population sizes, may explain why the 1987 sampling sites appeared to be without bogidiellids in 1996. However, the 1996 trip led to the discovery of a new mesopsammic species, B gidiella (Medigidiella) arista, as well as a new record of B. calicali G. Karaman, previously reported only from Rio di Quirra, Sardinia (Karaman, 1988b). Taxonomy within the genus Bogidiella appears far from being resolved. Various criteria for a division into several subgenera are applied by different authors, so that in some cases it remains unclear as to which species can be grouped together, for example, membership in the subgenus Medigidiella Stock, 1981. An unstable taxonomy, however, is not especially restricted to the genus Bogidiella, but is rather a common problem among amphipods. The reasons for taxonomic problems in the amphipod genus Niphargus, given by Hovenkamp et al. (1984), characterize the situation of stygobiont amphipods in general. The overall interspecific similarity of their phenotypic appearance is relatively high, which, in combination with (often unknown) geographical and/or seasonal variability, complicates the classification of new species. The accuracy and completeness of species descriptions vary considerably. Many species descriptions are based on very few specimens, often with body parts missing or of one sex only. Hertzog (1933) erected the genus Bogidiella with the discovery of his new species B. albertimagni from the subterranean fresh waters of the Rhine valley, Germany (see Karaman, 1979a). The discovery of new bogidiellids, however, has been increasing constantly over the last two decades, but their phylogeny is more or less unrevealed so far.

A new monotypic genus of Spelaeogriphacea is described from the Upper Jurassic of Liaoning Province, north-east China. This new genus and species brings the number of known spelaeogriphacean taxa to four, the others being two recent forms from Brazil and South Africa, and one from the Carboniferous of eastern Canada. The new Chinese form is morphologically(and phylogenetically) very similar to the recent spelaeogriphaceans, suggesting that the body plan seenin the recent Spelaeogriphacea was achieved relatively early in the history of the group. A cladistic analysis of this and several other peracaridan orders indicates that the Spelaeogriphacea may be a paraphyletic group. This suggests that much work remains to be done with respect to the taxonomy and phylogenetic relationships among the peracaridan taxa.

The Mazon Creek Cycloidea contain four taxa: Cyclus americanus Packard, 1885, Cyclus obesus, new species, Halicyne max, new species, and Apionicon apioides, new genus, new species. We conclude, based on a cladistic analysis, that cycloids are specialized maxillopodan crustaceans and a possible sister group to the Copepoda. They may have filled a niche similar to modernday crabs.

We present a cladistic analysis of the Cirripedia Thoracica using morphological characters and the Acrothoracica and Ascothoracida as outgroups. The list of characters comprised 32 shell and soft body features. The operational taxonomic units (OTUs) comprised 26 well-studied fossil and extant taxa, principally genera, since uncertainty about monophyly exists for most higher ranking taxonomic units. Parsimony analyses using PAUP 3.1.1 and Hennig86 produced 189 trees of assured minimal length. We also examined character evolution in the consensus trees using MacClade and Clados. The monophyly of the Balanomorpha and the Verrucomorpha sensu stricto is confirmed, and all trees featured a sister group relationship between the `living fossil' Neoverruca and the Brachylepadomorpha. In the consensus trees the sequential progression of `pedunculate' sister groups up to a node containing Neolepas also conforms to current views, but certain well-established taxa based solely on plesiomorphies stand out as paraphyletic, such as Pedunculata (=Lepadomorpha), Eolepadinae, Scalpellomorpha and Chthamaloidea. The 189 trees differed principally in the position of shell-less pedunculates, Neoverruca, the scalpelloid Capitulum, and the interrelationships within the Balanomorpha, although the 50% majority rule consensus tree almost fully resolved the latter. A monophyletic Sessilia comprising both Verrucomorpha and Balanomorpha appeared among the shortest trees, but not in the consensus. A tree with a monophyletic Verrucomorpha including Neoverruca had a tree length two steps longer than the consensus trees. Deletion of all extinct OTUs produced a radically different tree, which highlights the importance of fossils in estimating cirripede phylogeny. Mapping of our character set onto a manually constructed cladogram reflecting the most recent scenario of cirripede evolution resulted in a tree length five steps longer than any of our shortest trees. Our analysis reveals that several key questions in cirripede phylogeny remain unsolved, notably the position of shell-less forms and the transition from `pedunculate' to `sessile' barnacles. The inclusion of more fossil species at this point in our understanding of cirripede phylogeny will only result in even greater levels of uncertainty. When constructing the character list we also identified numerous uncertainties in the homology of traits commonly used in discussing cirripede evolution. Our study highlights larval ultrastructure, detailed studies of early ontogeny, and molecular data as the most promising areas for future research.

We describe a new species of pygocephalomorph eumalacostracan from the Leitchfield Formation, Mississippian (Lower Carboniferous) of Kentucky, U.S.A. The fossils display a well-developed cephalothorax, pleon, and tail fan, and they show greatest affinity with other species within Tealliocarididae, especially to species of Pseudotealliocaris. The new species, Pseudotealliocaris holthuisi, is a second taxon of tealliocarid from the American Lower Carboniferous, the other being P. palinscari from the Mississippian of Pennsylvania. We compare the new species to other known species in the family and provide an overview of pygocephalomorph evolution.

Phylogenetic Uncertainty.— Invertebrate zoologists have long debated the relationships of biramous-limbed Crustacea to other groups of arthropods. Haeckel (1866) recognized two groups of arthropods on the basis of respiratory anatomy. The Carides included the crustaceans, trilobites, xiphosures, and eurypterids; and the Tracheata, included the arachnids, insects, and myriapods. Work on the onychophorans (Mosely, 1874) indicated a link between annelids and the terrestrial myriapod-insect line, but this left the origins of the aquatic carides unresolved. Lankester (1881) demonstrated that the xiphosures were allied to the arachnids rather than to the crustaceans. These and other studies led Haeckel (1896) to revise his position and propose two separate lines of arthropods: one of primarily aquatic groups with primitively biramous appendages (crustaceans, trilobites, and chelicerates); and the other of primarily terrestrial groups with uniramous limbs (onychophorans, myriapods, and insects). Haeckel's new arrangement emphasized the convergent origins of trachea in the arachnids and uniramians. Korschelt and Heider (1890) preferred a monophyletic scheme with the two evolutionary lines united by a pre-onychophoran, “protostracan,” ancestor. By modern standards, however, this might indicate that the arthropods are a morphological grade, rather than a true clade.

[Two new species of Platythelphusa (Decapoda, Potamoidea, Platythelphusidae), are described from Lake Tanganyika. P. immaculata sp. nov. and P. praelongata sp. nov. are distinguished from congeners by a combination of diagnostic characters of the carapace, chelipeds, and pereiopods. Platythelphusa denticulata Capart, 1952, is removed from synonymy with P. conculcata . This brings the number of platythelphusid species reported from Lake Tanganyika to nine. A key is provided to separate the species of Platythelphusa . Deux especes nouvelles de Platythelphusa (Decapoda, Potamoidea, Platythelphusidae), sont decrites du lac Tanganyika. P. immaculata sp. nov. et P. praelongata sp. nov. se distinguent de leurs congeneres par une combinaison de caracteres diagnostiques concernant la carapace, les chelipedes et les pereiopodes. Platythelphusa denticulata Capart, 1952 est retire de la synonymie avec P. conculcata . Ceci porte le nombre des especes de Platythelphusidae connues du lac Tanganyika a neuf. Une cle est fournie pour separer les especes de Platythelphusa . , Two new species of Platythelphusa (Decapoda, Potamoidea, Platythelphusidae), are described from Lake Tanganyika. P. immaculata sp. nov. and P. praelongata sp. nov. are distinguished from congeners by a combination of diagnostic characters of the carapace, chelipeds, and pereiopods. Platythelphusa denticulata Capart, 1952, is removed from synonymy with P. conculcata . This brings the number of platythelphusid species reported from Lake Tanganyika to nine. A key is provided to separate the species of Platythelphusa . Deux especes nouvelles de Platythelphusa (Decapoda, Potamoidea, Platythelphusidae), sont decrites du lac Tanganyika. P. immaculata sp. nov. et P. praelongata sp. nov. se distinguent de leurs congeneres par une combinaison de caracteres diagnostiques concernant la carapace, les chelipedes et les pereiopodes. Platythelphusa denticulata Capart, 1952 est retire de la synonymie avec P. conculcata . Ceci porte le nombre des especes de Platythelphusidae connues du lac Tanganyika a neuf. Une cle est fournie pour separer les especes de Platythelphusa . ]

An expanded series of morphological characters developed for a cladistic analysis of extant decapods has yielded a new hypothesis for the phylogeny of the group. Application of this database to selected fossil genera produces some interesting results and demonstrates the feasibility of treating fossils as full and equal partners in the study of decapod phylogenetic relationships. In addition, it seems clear that rigorous cladistic methods can be used to evaluate the phylogenetic positions of fossils, rather than ad hoc speculation.

Review of and commentary on: Body Cavities: Function and Phylogeny, edited by G. Lanzavecchia, R. Valvassori, and M.D. Candia Carnevali. Mucchi Editore/Modena, 1995, 280 pp., ISBN 88-7000-259-4. “The time has come”, the Walrus said, “To talk of many things: Of shoes – and ships – and sealing wax – Of cabbages – and kings – And why the sea is boiling hot – And whether pigs have wings.” Louis Carroll

Traditional views of eumalacostracan phylogeny are not in accord with current understanding of the fossil record. Another approach results from identification of basic morphotypes upon which radiations were built in the course of eumalacostracan history. Random association of characters (absence or varying conditions of the carapace, biramous or uniramous thoracopods, and presence or absence of subthoracic brood pouch of some form) yields an array of 16 morphotypes, of which 10 are recognized in the fossil and Recent record. The resultant "paper animals" combined with an analysis by cladistic methods yield six possible phenograms of eumalacostracan phylogeny. An evolutionary uncertainty principle precludes definitive choice among these patterns to produce a cladogram and taxonomy. However, a taxonomic system is advocated with the subjectivity associated with uncertainty clearly acknowledged. Perhaps one of the greatest noncontroversies in crustacean evolution has been the phylogeny and interrelationships of the Eumalacostraca. Since Calman (1904, 1909) it has been taken for granted that the higher malacostracans could be classified as discreet superorders which were derived from an ancestral type neatly delineated by a set of characters known as the caridoid facies. However, Calman's synthesis was the result of several decades of debate over how malacostracan groups were related. Boas (1883) visualized a single line arising from the phyllopods and giving off the malacostracan groups at successive levels. Claus (1885) envisioned three branches arising from a "eumalacostracan" stock: leptostracans, stomatopods, and "urschizopods," and this was essentially Grobben's (1892) position as well, except that Grobben had the stomatopods as the earliest offshoot from the "urschizopods.' Haeckel (1896) derived his "proschizopods" from the Leptostraca and in turn treated these as an ancestral stock for five lines: mysids, cumaceans, other "peracarids," "eucarids," and stomatopods. Calman's caridoid concept, however, exerted a stablizing influence on all succeeding speculations on higher malacostracan phylogeny, with the result that subsequent phyletic schemes for these groups have been essentially similar (Giesbrecht, 1913; Grobben, 1919; Balss, 1938; Siewing, 1956, 1963; and Brooks, 1962). Of these, Siewing came to be a focus of a certain school (viz., Fryer, 1964; Hessler, 1969) which essentially holds that all eumalacostracan superorders arose from a central stem. Schram (1969a, b) recently suggested that the Hoplocarida had nothing to do with other Eumalacostraca, but rather had an independent origin separate from the Eumalacostraca sensu stricto. This latter position was objected to by Burnett and Hessler (1973) but supported by Reaka (1975), Bowman and Abele (in press), and Kunze (personal communication). Through all this, the essential stability and supposed interrelationships of the Eumalacostraca sensu stricto, viz., syncarids, eocarids, peracarids, pancarids, and eucarids has remained relatively constant. The Eocarida and Syncarida were interpreted as near the base of the eumalacostracan line; and supposedly from somewhere within the eocaridan stock the Eucarida and Peracarida were derived, with the Pancarida seeming to bear some relationships to peracarids (some authors placing them as a separate superorder and others as an order of peracarids). This traditional arrangement of orders is outlined in Fig. 1.

Schram, F. R. (Dept. of Zool., Eastern Ill. U., Charleston, lll. 61920) 1974. Convergences between Late Paleozoic and modern caridoid Malacostraca. Syst. Zool. 23:323-332.-Study of the Middle Pennsylvanian, Mazon Creek, Essex fauna Crustacea (Johnson and Richardson, 1966; and Richardson and Johnson, 1971) of northeastern Illinois has prompted an examination of the entire Late Paleozoic radiation of caridoid malacostracans. Members of this radiation bear several gross anatomical similarities to Mesozoic-Cenozoic eucarid forms, yet are totally and completely distinct taxonomically from them. This convergent phenomenon affords a rare look at the evolution of a major taxonomic category extending over a period of some 300 million years. The comparison also bears on general theoretical considerations of diversity and convergence in evolutionary theory. [Convergence; Malacostraca; Diversity models.] The malacostracan crustaceans have been present in the fossil record since Cambrian time. The earliest and more primitive forms have been the Phyllocarida, forms with seven segments in their abdomens. In Devonian time a more advanced array of malacostracans apparently evolved from the phyllocarids. These forms, the Hoplocarida and the Eumalacostraca, are characterized by having six segments in the abdomen and a great variety of tagmatic and appendicular specializations that enabled them to more effectively dominate their environments. The Late Paleozoic radiation of advanced malacostracans was composed of hoplocaridans, syncaridans, and primitive eumalacostracans variously termed Eocarida (Brooks, 1962), caridoids, or schizopods. The Hoplocarida almost completely died out at the close of the Paleozoic except for the specialized Stomatopoda or "mantis shrimp." The caridoids persisted and formed the basis of the modern malacostracan radiation. The caridoids are all characterized by an array of features first elucidated by Calman (1909): two flagella on the first antenna, two segments in the thoracic protopod, five segments in the thoracic endopod, annulate and natatory thoracic exopods, thoracic epipodite gills, thorax and abdomien subequal, thorax containing viscera and covered by a carapace, abdomen developed with a special musculature for the distinctive backward-swimming caridoid escape reaction. These primitive caridoids gave rise to the groups which are the dominant malacostracans today, the Eucarida and Peracarida. The Peracarids have developed a brooding habit for protecting the young, and morphologically have a tendency to lose the carapace and greatly modify the body regions so as to diverge markedly from the caridoid morphotype. The evolution of the peracarids proper must remain the subject of another paper. The Eucarida have more closely retained the caridoid facies and are the dominant caridoid types today. The only living peracarids that can be termed "caridoid" are the Mysidacea. PERIPATETIC TAXONOMY The taxonomic affiliations of the Late Paleozoic caridoid malacostracans have been realigned several times. Huxley (1857) termed Pygocephalus cooperi an early form of decapod (Brooks, 1969, has since assigned this species to the genus Crangopsis). Huxley's designation influenced subsequent workers to categorize their fossil species as "macrurous decapods" as in Etheridge's (1877) description of some specimens of Anthrapalaemon and Wood

We present a cladistic analysis of the crustacean class Remipedia, including all 17 extant species currently assigned to the order Nectiopoda, with the Carboniferous fossil Tesnusocaris serving as an outgroup. We applied different methodological approaches and coding options to a basic matrix composed of 26 morphological characters. Our analyses strongly support monophyly of the Godzilliidae and affirm justification of the family Micropacteridae. However, the present taxonomic structure within the Speleonectidae is partly incompatible with our results, and we cannot exclude that the family is paraphyletic.