824


Journal of Paleontology 92(5):804–837


34.7mm. Typical shell size of specimens from UF locality YN020: moderately small (23.4mm; N=87). Last whorl.—Shape typically broadly conical, sometimes


conical (RD 0.69–0.80, x=0:75; PMD 0.89–0.94, x=0:92; N=24); outline slightly sigmoidal (posterior half convex, anterior half concave). Shoulder carinate or sharply angulate, smooth. Widest point of shell at shoulder. Aperture uniform in width from base to shoulder. Siphonal notch absent. Prominent ribs extend from base to shoulder; ribs on the anterior half are sometimes beaded. Grooves between ribs exhibit prominent axial threads that result in a cancellate pattern (Fig. 10.7); grooves often decrease in width towards the shoulder. Spire whorls.—Spire moderate to high (RSH 0.21–0.30,


x=0:25;N=24); outline often slightly sigmoidal (concave near apex; convex near later whorls). Protoconch multispiral, with at least 3.5 whorls; diameter 0.8–0.9mm (x=0:9; N=14). Tubercles present on first 0.5–1.75 whorls; these become diminishing undulations before terminating (Fig. 10.4). Early whorls strongly stepped; later whorls weakly stepped. Sutural ramp usually concave, but may be nearly flat or slightly sig-


moidal; very fine spiral grooves sometimes present. Subsutural flexure asymmetrical (ASSF 0.3–0.5, x=0:4, N=5), depth usually slightly less than width (DWSSF 0.7–1.3, x=0:9, N=5) (Fig. 10.5, 10.6). Coloration pattern.—One pattern present. Pattern consists


of pigmented dashes or blotches on rib surfaces that are often organized into axial streaks or blotches; an unpigmented or weakly pigmented region is often present just anterior to the midline of the last whorl, dividing the regions of pigmentation into two broad, discontinuous bands. In one observed specimen (UF 259862; Fig. 10.17), pigmentation on the rib surfaces nearly form two solid bands just above and below the midline. In another specimen (UF 271002, Fig. 10.18), very well orga- nized axial streaks are present. Sutural ramp with irregularly shaped pigmented radial blotches.


Materials.—USNM645751 (one specimen, figured byWoodring, 1970; Fig. 10.1); ANSP 2554, the syntype series (nine specimens, all from the Gatun Formation) of Conus gaza, including the spe- cimen illustrated by Brown and Pilsbry (Fig. 10.2), and an addi- tional 156 observed specimens, all from UF locality YN020, which are listed in Supplementary Data Set 1.


Remarks.—Woodring (1970) reported that the type specimen of Conus multiliratus is lost and communication with the staff of the Instituto de Geología at the Universidad Nacional de México in 2010 confirms that this remains the case. Nevertheless, the specimens figured by Böse from Tuxtepec, Mexico appear consistent in form with the specimens considered here from the Gatun Formation, allowing them to be confidently assigned to the same species. Inspection of the syntype series in ANSP 2554 supports the conclusion of Woodring (1970) that Conus gaza is a junior synonym of Conus multiliratus. Hendricks (2015) assigned the fossil species to the genus


Conus and the subgenus Dauciconus sensu Puillandre et al. (2014, 2015) because the overall shell morphology of Conus multiliratus is very similar to that of the extant western Atlantic species Conus (Dauciconus) cancellatus Hwass in Bruguière, 1792 (see Kohn, 2014 for a recent circumscription). This


assignment is considered more tentative here, however, because shells of C. multiliratus are also broadly similar to extant taxa assigned to the subgenus Conasprella (Kohniconus) sensu Puillandre et al. (2014, 2015). For example, specimens of the eastern Pacific species Conasprella (Kohniconus) arcuata (Broderip and Sowerby I, 1829) figured by Tenorio et al. (2012, pl. 228, figs. 1a–11b) have shell shapes, coloration patterns, and ornamentation features that are also generally consistent with those of C. multiliratus; perhaps importantly, however, weak spiral ornamentation is sometimes present on the sutural ramp of C. multiliratus, but is apparently absent from Conasprella arcuata (Tenorio et al., 2012). Tucker and Tenorio (2009, p. 146) noted this apparent convergence of form between the Conasprella (Kohniconus) and Conus (Dauciconus) clades: “[s]ome species of Kohniconus…have been confused…with species of Dauciconus” and this “underscores the utility of radular morphology in confirming identifications for such conchologically similar but distantly related species.” Tucker and Tenorio (2009), however, assigned C. cancellatus as the type species for the genus Conasprelloides, not Dauciconus. Puillandre et al. (2014) showed Conasprelloides sensu Tucker and Tenorio (2009) to be polyphyleticwithinConus (Dauciconus) sensu Puillandre et al. (2014, 2015). While information about the radula of C. multiliratus will likely never be recovered, construction of detailed morphological diagnoses ofmodern cone snail clades informed by molecular phylogenetic results (e.g., Puillandre et al., 2014, 2015) may help to clarify the phylogenetic position of this fossil species in the future. Pending completion of such work, C. multiliratus remains tentatively assigned to Conus (Dauciconus) sensu Puillandre et al. (2014, 2015). Hendricks (2015) reported on the coloration pattern of


Conus multiliratus from the lower Pliocene Gurabo Formation of the Dominican Republic. He demonstrated the presence of two continuous spiral bands on the last whorl that might be overprinted by spiral dashes. This varies significantly from the coloration pattern described here for specimens from UF locality YN020. Additional work is needed to determine if this amounts to a species-level difference, or instead an example of coloration pattern variation (or, potentially evolution) within a single lineage. While some specimens of extant Conus cancellatus have patterns that are consistent with C. multiliratus from the Dominican Republic (e.g., Kohn, 2014, pl. 69, figs. 16, 17), others have patterns that are generally consistent with the specimens documented here from the Gatun Formation (e.g., Kohn, 2014, pl. 69, fig. 12). Among co-occurring fossil species at UF locality YN020,


Conus multiliratus might be confused with Conasprella burckhardti, which also has strong ribs (also with intervening grooves showing prominent axial threads) that extend from the base of the last whorl to the shoulder. Shells of Conus multiliratus, however, are much wider than shells of Conasprella burckhardti and the two species do not overlap in RD. Conus multiliratus also bears some similarity in shape to Conasprella imitator, but the latter species has a very different coloration pattern, a greater number of tuberculate postnuclear whorls, and the spiral ornamentation on its last whorl is restricted to the anterior half. Conus multiliratus was the third most commonly collected species of Conidae at UF locality YN020.


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