Archierato maugeriae (Gray in Sowerby I, 1832) Fehse & Simone, 2020

Fehse, Dirk & Simone, Luiz Ricardo L., 2020, Contributions to the knowledge of the Eratoidae. X. Revision of the genus Archierato Schilder, 1933 (Mollusca: Gastropoda), Zootaxa 4851 (1), pp. 81-110 : 88-89

Archierato maugeriae (Gray in Sowerby I, 1832) comb. nov.

( Figs. 7 , 32 , 40 )

Erato maugeriae Gray in Sowerby I, 1832: 14 (fig. 47); Sowerby I, 1859: 11 (figs. 7, 9.); Smith, 1910: 14.

Hespererato maugeriae maugeriae: Schilder, 1933: 249 , 254, 267 (fig. 44); Allan, 1956: 144.

Erato (Hespererato) maugeriae: Abbott, 1974: 147 (fig. 1618).

Hespererato martinicensis: Cate, 1977: 361 (figs. 43, 43a) (non Schilder, 1933 C).

Erato emmonsi: Petuch, 1994 : pl. 24 (fig. H) (non Whitfield, 1894).

Hespererato maugeriae: Simone, 2004: 122−125 (figs 44, 100, 415−427); 2011: 167, 270, 277, 284, 291, 298, 305. Hespererato emmonsi: Petuch & Drolshagen, 2011: 266 (pl. 4.39, figs. K, L) (non Whitfield, 1894).

? Hespererato maugeriae: Petuch & Myers, 2014: 152 (fig. 7.5E).

Lectotype. NHMUK 197410 /1; Hugh Cuming collection; designation by C.N. Cate (1977: 361). L 5.2 mm, W 3.7 mm, H 3.2 mm, CT 14 LT 16

Type locality. Cedar Key , Levy County, Florida, Gulf of Mexico, USA. 29°07’N, 83°03’W ( Cate 1977: 361) .

Etymology. Named in honor of a woman named Maugerie known to the author of the species.

Original description (Sowerby I, 1832: 14). “ Erato maugeriae —Shell somewhat conical, turbinate, livid; spire very short, last volution ventricose, very obtusely angular behind; outer lip thickened, nearly white, toothed along its inner margin; a very few distinct teeth near the front [abapical end] of the columellar.”

Diagnosis. Shell mid-sized with length 5 to 6 mm, robust, rhombic, with close-set, coarse, somewhat obscured labral and irregular, less developed columellar dentition; ventral fold thickened, 16 labral and 14 columellar teeth; maximum globosity at posterior third.

Description. Shell mid-sized, rhombic, with elevated spire. Protoconch and subsequent whorls covered by thin callus. Suture slightly indistinct. Body whorl ~80% of total height, maximum diameter at posterior third, convexly tapered anteriorly. Anterior ventral margin largely indented. Dorsum roundly edged. Dorsal sulcus absent. Whole shell surface covered by very thin, callus sub-glossy. Aperture ~75% of total height, sinuous, narrow. Labrum narrow, ventrally sinuously shaped, thickened, smooth, rounded ventrally. Outer labral margin rounded, callused, edged at inner margin. Labral teeth coarse, less developed, close-set, irregular, 16 in number, restricted to labral edge. Siphonal canal short, rounded and blunt. Anal canal simple, indented. Columella sinuous, curved without inner carinal ridge, slightly developed parietal lip. Columellar denticles 14 in number, irregular, coarse, spaced, anterior most forming terminal ridge, posterior most enlarged, projecting. Fossula obscured, not delimited from the columella.

Callosities white; dorsum light red-brown; tips of canals and protoconch and first whorls brown.

Variability. The shells are more or less inflated and the spire more or less elevated. Dead-collected shells of A. maugeriae also stand out by their pale brown dorsum. The fine labral dentition is uniformly in strength and appearance. The general shell outline varies only slightly in the examined specimens from Florida, Honduras and Brazil.

Distribution. Florida to Panama. The following locality data could not be confirmed because the studied material was not available: ‘Hatteras to Antilles and Colon; West Fla. and Vera Cruz’ (Maury, 1922: 114); ‘… from North Carolina, both coasts of Florida, …’ ( Cate, 1977: 361). Plio-Pleistocene: Griffin Bros. pit, Holey Land area, Palm Beach County, Florida, U.S.A. ( Petuch, 1994: pl. 24, fig. H; Petuch & Drolshagen, 2011: pl. 4.39, figs. K, L).

Examined material. E. Panama: Charao Azul (DFB 7466).

Remarks. Cate (1977: 361) mentioned Brazil as the southernmost distribution for this species. Unfortunately, this could not be confirmed, and even Cate did not show or refer to a specimen in a public collection originating from there. Agudo-Padrón et al. (2009: 5) mentioned the occurrence of A. maugeriae in the Santa Catarina State of Brazil but did not show a specimen. Their identification cannot be confirmed.

Archierato maugeriae is the second colourful taxon within the genus similar to the eastern Pacific A. columbella . The Caribbean species differs from the latter by the smaller size, the rhombic instead of pyriform shell outline, the close-set, less developed labral denticles, the projecting posterior-most columellar denticle, the short siphonal canal, the sinuous aperture, the roundly edged dorsum, the roundly callused labrum without a sloped anterior portion and the ventrally sinuously shaped labrum. Archierato panamaensis is distinguished in the same way from A. maugeriae and also less colourful (see discussion above). The shape of A. galapagensis is separated immediately by the quite different shell outline.

The common English name of Archierato maugeriae is “green Erato ” (e.g., Itis 2017). It is seemingly based only on interpretations that are unaware of the real coloration and shell morphology of the type specimen. All Caribbean Erato are usually called ‘ Hespererato maugeriae ’ ( Abbott 1974: 147; Cate 1977: 361) without scrutinizing the possible existence of different species. An in-depth study of material collected throughout the Caribbean, however, presents a higher diversity than ever presumed and the usually called ‘green Erato ’ presents a different species described herein (compare Archierato janae ).

Redfern (2001: 54, pl. 24, fig. 231) published on a specimen from beach drift from Abaco, Bahamas with ‘olivegreen’ dorsum. The dorsal coloration resembles the holotype of A. martinicensis but the shell outline differs slightly and the labral dentition is somewhat coarser. No specimens were available for study. Therefore, the identity of the Erato from Bahamas is uncertain.

Schilder (1933: text fig. 44, 45) published drawings of A. maugeriae and A. martinicensis where folds are indicated on the mid-ventrum. However, these folds are not seen on the shells. The drawing of A. maugeriae also shows labral denticles extended as folds. Such folds are not found in this taxon. Therefore, Schilder’s drawings are misleading.

Petuch (1994: pl. 24, fig. H) showed a specimen that he identified as ‘ Erato emmonsi Whitfield, 1894 ’ from Griffin Bros. pit, Holey Land area, Palm Beach County, Florida, U.S.A., early Pleistocene, and a specimen (1994: pl. 24, fig. G) called ‘ Erato maugeriae Gray, 1832 ’ from North New River Canal, South Bay, Palm Beach County, Florida, U.S.A. The shell of ‘ E. emmonsi ’ is almost identically to the lectotype of A. maugeriae and one might suspect that Petuch mixed up the photos. But Petuch & Drolshagen (2011: pl. 4.39, fig. K, L) showed a second specimen called ‘ Erato maugeriae Gray, 1832 ’, from Griffin Bros. pit, Holey Land area, Palm Beach County, Florida, U.S.A., too, that is again almost identical to the lectotype of A. maugeriae .

Petuch & Myers (2014: text fig. 7.5E) published a dorsal view in small size of an Erato . A dorsal view and generally small sized photos of minute shells are not enough for a safe identification. The unique brown shell coloration as well as the shell outline resembles closely the lectotype of A. maugeriae but it also resembles A. guadeloupensis .

Figures

FIGURES 7–9. Archierato type specimens. 7. Archierato maugeriae (Gray in Sowerby I, 1832) lectotype NHMUK 197410/1, L 5.2 mm “Levy County, Florida, U.S.A.” (courtesy H. Taylor). 8. Archierato columbella (Menke, 1847) neotype LACM 3302, L 6.8 mm, White Port, Los Angeles County, California, USA (courtesy L.T. Groves). 9. Archierato panamaensis (Carpenter, 1856) lectotype NHMUK 1966619/1, L 7.5 mm, ‘Pacific Panama’ (courtesy H. Taylor).

FIGURES 30–32. Archierato specimens. 30. Archierato janae nov. sp. holotype ZSM 20171203. L 5.7 mm, off Hypoluxo, Florida, S.A. 31. A janae paratype MSF MAM tv14, L 6.3 mm, off Hypoluxo, Florida, USA. 32. Archierato maugeriae (Gray in Sowerby I, 1832) DFB 7466, L 4.9 mm, Charao Azul, E Panama.

FIGURES 36–41. Comparison of the W Atlantic Archierato species (the shells are equally sized for better comparison, consider, e.g., Tab. 1 for their real dimension). 36. A. guadeloupensis, holotype. 37. A. dalli, holotype. 38. A. dalli, off Florianópolis, Santa Catarina State, Brazil. 39. A. martinicensis, holotype. 40. A. maugeriae, lectotype. 41. A. janae, holotype.