470
Journal of Paleontology 92(3):466–477
with slightly rounded tips. Orbits very large for the genus, rounded, with two well-defined supraorbital notches; inner notch parallel to carapace axis; outer notch directed towards median line. Inner orbital corners pronounced, raised; outer orbital corners more subtle and depressed. Anterolateral margin convex, slightly raised, with nine teeth (includes outer orbital tooth); a tenth weakly developed and low tooth on the poster- olateral margin; all teeth sharp, triangular, lined with small granules; teeth 4–5, 6–7, and 8–9 clustered, more depressed than preceding teeth; these groups of two teeth limited by a deeper notch; teeth 4–5 slightly forwardly directed, teeth 6–7 and 8–9 perpendicular to lateral carapace margin. Posterolateral margin gently concave, lined by a distinct, finely granular rim, fading into rounded posterior corner. Posterior margin gently rounded, weakly concave medially, narrower than orbitofrontal margin. Protogastric regions large, U-shaped; mesogastric region sharply triangular, with rounded posterior margin, containing well-visible widely separated gastric pits; cardiac region large, well defined, hexagonal. Chelipeds massive; merus triangular in cross-section, preserved cuticle with granular lower margin and a distinct tubercle at the distal joint. Outer surface of carpus smooth or slightly granular, without keel; a line of granules highlights the angular margins. Propodus with flattened and hollowed inner surface; preserved cuticle of external face of palm characterized by four blunt equidistant granular crests; upper margin tubercular with a tooth near the articulation with the carpus. Dactylus flattened, high, with external granular rim,
and inner margin with a dozen small and sharp teeth. Fixed finger with small, sharp teeth. Walking legs rather short, laterally compressed, with narrow, straight, styliform dactyls. Dorsal carapace with smooth surface microstructure in
small individuals, preserved cuticle finely granular or areolate in larger specimens in particular in the central regions.
Etymology.—The specific epithet honors the late Mrs. Françoise Noël, physician specializing in endocrinology.
Materials.—114 nodules (MNHN.F.A59115–A59219, A59618–A59626) containing more or less complete carapaces, some with partially preserved endoskeletons and chelipeds.
Remarks.—The new species fits well in the diagnosis of Romaleon because of its relative carapace ratios, a weakly concave posterolateral margin, anterolateral margin with nine sharply triangular teeth that are separated to their base and curved forwards, and the front, which is projected beyond the orbital level with the medial tooth at a lower level. Romaleon is a genus with Miocene species from Japan, California, and Patagonia, Argentina (Imaizumi, 1962; Kato, 1996; Kato and Hikida, 2002; Casadío et al., 2005); Pliocene–Pleistocene species from the west coast of North America (Molina, 1782; Stimpson, 1856; Rathbun, 1900, 1926), and extant species from Japan and the west coasts of North and South America (Molina, 1782; De Haan, 1833; Rathbun, 1900; Sakai, 1969, 1983). In Romaleon, the clustered anterolateral teeth 4–5, 6–7, and 8–9of R. franciscae n. sp. is only seen in the lower upper Miocene species from Patagonia, R. parspinosus. Romaleon parspinosus is morphologically closest to R. franciscae n. sp., however the orbits are clearly smaller, the orbitofrontal width (47%, vs 37%
in R. parspinosus) and posterior margin width (38% vs 20% in R. parspinosus) are much smaller, and the notches clustering the anterolateral teeth arecmore distinct in R. parspinosus. Casadío et al. (2005, p. 162) noted that Anisospinos
Schweitzer and Feldmann, 2000 (late Eocene, Washington, USA; Miocene, Washington, USA and Japan) also exhibits paired anterolateral teeth. However, Anisospinos has eight anterolateral teeth instead of nine, has no posterolateral spine instead of one, and has five frontal teeth that are evenly spaced, instead of the three median teeth clustered. Anisospinos is one of the oldest cancrid crabs and may be ancestral to Romaleon (see also Schweitzer and Feldmann, 2000, fig. 1). Within extant Romaleon, R. franciscae n. sp. resembles the
extant Japanese type species R. gibbosulum, but is distinguished by having its middle frontal tooth shorter than in the type species, by the two distinct notches of the orbital margin, the teeth of the anterolateral margin grouped in clusters of two and less anteriorly directed, and cheliped significantly less spinose. Romaleon luzonensis has a more areolated carapace, and distinct teeth on the posterolateral margin. Romaleon franciscae n. sp. is also morphologically close to R. branneri (Pliocene–Pleisto- cene, North America), whose frontal teeth are very similar; however, the anterolateral teeth of R. branneri end in a spine, which is not the case in R. franciscae n. sp. Another related species, R. jordani (Pliocene–Pleistocene to extant, North American), has a narrower PM of the carapace (20% vs 38% in R. franciscae n. sp.) and a cheliped with the propodus upper margin less tubercular. Romaleon franciscae n. sp. also resembles R. dereki (Miocene, California), but is distinguished by the presence of a tooth at the posterolateral corner, and by the teeth of the anterolateral margin less spiniform and assembled in pairs. Other species of Romaleon seem more distinctly different: R. antennarium (Pliocene to extant, North American Pacific) exhibits more spiniform anterolateral teeth, which are more anteriorly directed; R. nadaensis, an extant Japanese species, has the anterolateral teeth regularly spaced and equal in size; R. urbanus (Pliocene, California) shows deep grooves and depressions on the carapace, especially in the metagastric region; R. granti (Pliocene, California) lacks a tooth at the posterolateral margin and rows of large tubercles on the cheliped. Romaleon yanceyi (Pliocene or Pleistocene, California) is known only by two propodi of chelipeds that lack the spiny ornamenta- tion of R. franciscae n. sp. Romaleon nakagawaensis,from the Miocene of Japan, has smaller, more forwardly directed anterolateral teeth, and a weaker groove system on the dorsal carapace; R. sakamotoi has deeper, more acute carapace grooves, and more slender, pointed anterolateral teeth; and R. sanbonsugii has two small distinct posterolateral teeth or tubercles which distinguish it from R. franciscae n. sp.
Results
Bryozoan post-mortem fouling.—Two distinct bryozoan colo- nies are found on the internal mold of one of the largest crabs (Fig. 3.1, CW=42 mm). They correspond to hundreds of zooecia of cheilostomes preserved as basal imprints (Fig. 3.2). Diagnostic features are not preserved, so the colonies are not further identifiable. Some of the zooecia shapes may in some aspect evoke Calloporidae Norman, 1903 (K. Zagorsek,
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