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Subfamily Lobocarcininae Beurlen, 1930
Included genera. – Lobocarcinus Reuss, 1857; Miocyclus Müller, 1979; and Tasadia Müller in Janssen and Müller, 1984.
Diagnosis. – Carapace wider than long; front usually with even number of spines, ranging from four to six and if odd number of spines, central spine small and at lower level than other spines; orbits with two fissures; anterolateral margin typically with several anterolateral spines; spines well-developed, separated to base, often bifurcate or trifurcate; posterolateral margin typically coarsely granular or with well developed spines; posterior margin nearly straight, granular or spined; carapace regions typically moderately well-developed, ornamented with dense granules or with discrete, large spines.
Remarks. – The Lobocarcininae is a small subfamily comprised of three genera, two of which are monospecific. Miocyclus differs from the other two included genera in possessing fissured anterolateral spines and a smooth, entire posterolateral margin. However, it possesses an even number of frontal spines, a diagnostic character of the subfamily. Therefore, it is placed within the Lobocarcininae, although this placement can be considered to be provisional because the specimens have not been examined.
All of the genera within the Lobocarcininae have their earliest occurrence in or are known solely from the Tethys, and in fact, only one species of Lobocarcinus, L. pustulosus Feldmann and Fordyce, 1996, is extralimital. This suggests that the subfamily arose in the Tethyan region, as early as the middle Eocene, and subsequently dispersed into New Zealand waters.
Lobocarcinus Reuss, 1857
next sectionType species. – Lobocarcinus paulinowuerttemburgensis von Meyer, 1847.
Diagnosis. – Carapace much wider than long. Front projected weakly beyond orbits; four to six frontal spines including inner orbital spines. Fronto-orbital width from 30 to 40 percent maximum carapace width; orbits round, with two fissures, directed forward; orbits rimmed. Anterolateral margin usually with seven lobes; lobes typically sharply bifurcate or trifurcate. Posterolateral margin nearly straight, with several spines of varying size. Posterior margin nearly straight, sometimes with spines. Regions moderately well-developed, often ornamented with several large nodes. Chelipeds slender and equal.
Remarks. – Six species are referred to the genus Lobocarcinus. All are known from the Tethyan region with the exception of L. pustulosus, known from the Miocene of New Zealand (Feldmann and Fordyce, 1996). A complete discussion of the group was provided by Anderson and Feldmann (1995), who revised the genus and described a new species. Lobocarcinus pentanodosus Collins and Barber, 1998, was reported from Eocene rocks of Indonesia; however, that species has fewer anterolateral spines than do species of Lobocarcinus and the spines of L. pentanodosus are singular, not bifurcate or trifurcate as in authentic Lobocarcinus. The posterolateral margins of L. pentanodosus are entire, while those of authentic Lobocarcinus are spined. The carapace ornamentation of L. pentanodosus differs from that of authentic Lobocarcinus. Typical members of Lobocarcinus possess large granules on the carapace and rather well defined carapace regions. Lobocarcinus pentanodosus has poorly defined regions and transverse ridges on the protogastric regions. The transverse ridges and the possession of five, singular anterolateral spines suggest that L. pentanodosus may be a portunid.
Cancer sismondae is here referred to the genus Lobocarcinus based upon its possession of distinctly lobed anterolateral margins, spined posterolateral margins, and the overall shape of the carapace and carapace regions (Bonfiglio and Donadeo, 1982). The carapace regions appear to be ornamented with nodes, as is typical of many species of Lobocarcinus. The only difference between L. sismondai and other species of Lobocarcinus is that it possesses five frontal spines, including an axial spine instead of an even number as is typical of the genus and subfamily. This constitutes a major difference; however, all other carapace characters clearly place L. sismondai within Lobocarcinus. The axial spine is smaller than the other spines and placed at a lower level, a condition seen in many members of the Cancrinae and which could represent convergence. It is also recognized that Cancer illyricus Bittner, 1893 and C. deshayesii A. Milne Edwards, 1861 are synonymous with L. sismondai (Glaessner, 1929; Müller, 1984; Collins and Fraaye, 1991). Specimens of these taxa were not seen by us, but the synonymy of these taxa is well-demonstrated in the cited works.
The genus is known only from the fossil record, occuring in middle to late Eocene rocks of Egypt, Hungary, and India; Miocene rocks of New Zealand; and Miocene to Pliocene rocks of the Mediterranean rim and Northern Europe. Feldmann and Fordyce (1996) suggested that the genus evolved in the Tethys and subsequently dispersed from that region into New Zealand. Members of this genus are the earliest known members of the subfamily.
Miocyclus Müller, 1979
Type species. – Miocyclus bulgaricus Müller, 1979.
Diagnosis. – Carapace wider than long, flattened, ornamented with small, dense granules; orbits with two fissures; front weakly projecting beyond orbits, with six frontal spines including inner-orbital spines; anterolateral margin crispate, with nine spines; first eight fissured, with blunt margins; last spine sharp, produced; posterolateral margin entire, nearly straight; posterior margin weakly convex.
Remarks. – Miocyclus is a monospecific genus known from the Miocene of Bulgaria. It was originally placed within the Atelecyclidae by Müller (1979) but was later moved to the Cancrinae based upon possession of wide mesogastric regions (Müller, 1984). The genus is here placed within the Lobocarcininae based upon possession of an even rather than odd number of frontal spines. The genus is easily distingushed from other members of the Lobocarcininae because it lacks well-developed bifurcate or trifurcate spines on the anterolateral margin and has a smooth, entire posterolateral margin.
Tasadia Müller in Janssen and Müller, 1984
Cancer Bittner, 1884, p. 27, pl. 1, figs. 8-9; Lörenthey,1897, p. 159-160, 167-168.
Atelecyclus Lörenthey. Lörenthey in Lörenthey and Beurlen, 1929, p.156-158, pl. 9, fig. 9; gripp, 1969, pp. 86-87, pl. 3, fig. 1.
Cyclocancer (Lörenthey). Beurlen, 1958, p. 15.
Cancer (Glebocarcinus) Karasawa, 1990, p. 6.
Type species. – Cancer carniolica Bittner, 1884.
Diagnosis. – Carapace wider than long, L/W about 0.60. Front not projected beyond orbits, four or five frontal spines. Fronto-orbital width to width ratio about 30 percent; orbits small, shallow, directed forward, with two fissures. Anterolateral margin convex, ornamented with eight or nine triangular spines, with granules or spinelets, each separated to bases. Posterolateral margin nearly straight, granular, with several small spines. Posterior margin rimmed, nearly straight. Regions well defined, ornamented with densely spaced tubercles; regions defined by smooth, deep grooves.
Manus of chelipeds with at least four granular keels on outer surface; upper margin appearing to be ornamented with sharp spines; lower margin smooth. Fixed finger with two granular keels on outer surface. Movable finger with sharp granules on upper margin; at least one row of granules on outer surface.
Discussion. – Davie (1991) suggested that this genus exhibited sufficient similarity to the genus Platepistoma that it may be synonymous with it, whereas Karasawa (1990) synonymized Tasadia with Cancer s. l. Examination of illustrations and casts of specimens of Tasadia (Müller in Janssen and Müller, 1984, pl. 5) indicates that it is indeed a distinct genus. Tasadia differs from members of Platepistoma in possessing distinct, large, triangular anterolateral spines, while the anterolateral spines of Platepistoma are small and reduced. Additionally, Tasadia possesses a multi-spined posterolateral margin, while that of Platepistoma typically only has one spine. The regions of Tasadia are not as densely ornamented, and the shape of the regions differs in Tasadia from those of Platepistoma. Tasasdia is also distinguishable from Glebocarcinus, members of which typically have narrow, anterolateral spines that are directed weakly anteriorly and sometimes ornamented with spinelets. The anterolateral spines of Tasadia are short, broad, and triangular and are ornamented with large granules. The carapace regions of Tasadia are not nearly as well developed and are more sparsely yet more coarsely ornamented than those of Glebocarcinus. The orbits are better developed in Glebocarcinus and the frontal spines are much better developed than in Tasadia. For all of these reasons, Tasadia is retained as a distinct genus. As far as is known, Tasadia is a monospecific genus restricted to the Miocene of Central Europe. Cancer bittneri Toula, 1904 was recognized to be synonymous with T. carniolica by Müller (1984).