Frederick R. Schram

What is Cancer

ABSTRACT 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.

THREE NEW TANAID SPECIES (CRUSTACEA, PERACARIDA, TANAIDACEA) FROM THE LOWER CRETACEOUS ÁLAVA AMBER IN NORTHERN SPAIN

Marine crustaceans were not known as inclusions in amber from upper Aptian–middle Albian deposits in Northern Spain. The publication of a photograph of a purported fossil amphipod (Alonso et al., 2000) among many other arthropods promised to be of high interest because the fossil record of the amphipoda does not extend further than Upper Eocene (Schram, 1986; Coleman and Myers, 2000). The Museum of Natural Sciences of Alava in Vitoria-Gasteiz (AMNS), northern Spain, kindly sent us the material with the presumed amphipods, as our intention was to investigate its affinities to other fossil amphipods. The fossil crustaceans of this assemblage were found among 15 orders of insects, spiders, and mites—i.e., mainly terrestrial arthropods. Upon close investigation, however, we learned that the samples contained not amphipods but tanaids. This means that the fossil age of amphipods remains unchanged for the moment and other questions emerge, such as: how can a common looking, marine, subtidal tanaid end up in a 100–120 my piece of amber from a sedimentary environment in northern Spain? And how does it relate to the numerous insects and plant pollen enclosed in other pieces of amber from the same site? The sedimentary environment in the south of the Basque-Cantabrian Basin around Alava in Lower Cretaceous times was marked with distributary channels, crevasse splays, and interdistributary bays, evolving towards an open marine platform (Alonso et al., 2000; Portero and Ramirez del Pozo, 1979, personal commun. V. Pujalte). Where waters became stagnant in this environment and could no longer carry large particles in suspension, amber lumps of nearby forests were deposited. Flooding of the delta occurred from both marine incursions, as indicated by the presence of silt and dinoflagellate cysts in a coastal area, and fluvial influxes. It is under these floodplain conditions that tanaids, probably present …

Post‐embryonic development of remipede crustaceans

SUMMARY During diving explorations of anchialine cave systems on Abaco Island, Bahamas, we collected five larvae that represent different developmental stages of remipede crustaceans. Based on four early naupliar stages and a post‐naupliar larva, it is possible for the first time to reconstruct the postembryonic development of Remipedia some 25 years after their discovery. These specimens begin to fill in some critical gaps in our knowledge of this important group of crustaceans.

Phylogenetic Analysis and Systematic Revision of Remipedia (Nectiopoda) From Bayesian Analysis of Molecular Data

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.

Behavior of Remipedia in the laboratory, with supporting field observations

Abstract We observed in the laboratory the behavior of six individuals of an as yet undescribed species of Speleonectes (Remipedia) over a period of 76 days. The live specimens were collected from an anchialine cave on the Yucatan Peninsula and maintained in separate aquaria at the Zoological Museum Amsterdam. In addition, field observations were conducted in the same cave to compare the laboratory results with naturally occurring behaviors. We found a variety of complex behavioral traits that include several new and unexpected findings. For example, our observations suggest that remipedes are not obligatory, but rather facultative carnivores, and that filtering particles might be the predominant mode of feeding. A digital video with examples of various behavioral traits can be downloaded at http://www.tiho-hannover.de/einricht/botanik/research.htm.

PALEOZOIC PROTO-MANTIS SHRIMP REVISITED

Abstract A review and revision of the Paleozoic proto-stomatopods results in the recognition of a new species of Tyrannophontes Schram, 1969, T. gigantion, from the Middle Pennsylvanian Mazon Creek, Essex biota. A new family, Daidalidae, and new genus, Daidal, are required to separate a previously recognized taxon, T. acanthocercus Jenner, Hof, and Schram, 1998. Both Perimecturus pattoni Peach, 1908 and Gorgonophontes cf. fraiponti (Schöllmann, 2004) appear at present to be best placed within Daidal, the latter as a new species, D. schoellmanni. The genus Gorgonophontes Schram, 1984 is allocated to a new family, Gorgonophontidae. Members of the family Tyrannophontidae reveal features of their maxillipeds that clearly relate them as a sister group to Unipeltata. A cladistic analysis of all known Paleozoic Palaeostomatopoda Brooks, 1962 and Archaeostomatopodea Schram, 1969 reveals a series of stem-group proto-mantis shrimp that lead to the crown-group Unipeltata Latreille, 1825.

Two new species of Platythelphusa A. Milne Edwards, 1887 (Decapoda, Potamopidea, Platythelphusidae) and comments on the taxonomic position of P. denticulata Capaart, 1952 from Lake Tanganyika, East Africa

[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 . ]

Family level classification within Thylacocephala, with comments on their evolution and possible relationships

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.

New Malacostracan Crustacea from the Carboniferous (Stephanian) Lagerstätte of Montceau-les-Mines, France

Abstract Investigations of recently cracked concretions from the Carboniferous Montceau-les-Mines, France, Lagerstätte led to the recognition of two new malacostracan Crustacea: a palaeophreatoicid isopod, Sottyella montcellensis n. g., n. sp., and a gorgonophontid stomatopod, Chabardella spinosa n. g., n. sp. The occurrence of the palaeophreatoicid isopod Palaeocrangon is discussed, and a new specimen of the syncarid Palaeocaris secretanae allows us to clarify some of its morphological characters. The recognition of these taxa increases the faunal inventory of malacostracans in the Montceau-les-Mines Lagerstätte.

The Proof is in the Pouch: Tealliocaris is a Peracarid

Abstract Tealliocarid eumalacostracans, known from Late Devonian-Carboniferous marine, non-marine, and estuarine strata of North America, continental Europe, and the United Kingdom, are here transferred from Eucarida: Decapoda back to Peracarida: Pygocephalomorpha. Species included in Tealliocaris exhibit a suite of peracaridan and pygocephalomorphan synapomorphies, including the presence of an oostegite marsupium in females, a distinct terminal telson lobe, and a pair of lateral telson lobes. Purported decapodan characters, e.g. complete fusion of the carapace and thoracic tergites, and the presence of only five pereiopods, in Tealliocaris seem to be poorly supported. A phylogenetic analysis included herein fully supports inclusion of Tealliocaris in Peracarida and in Pygocephalomorpha.