Bollmannia ornatissima, Schwarzhans & Aguilera, 2024

Bollmannia ornatissima n. sp.

Figure 16c–g View Fig

Holotype NMB P15479 View Materials ( Fig. 16c View Fig ), Tortonian ( NN 10 ), Yaviza FM, Panama, Darien, Río Tuquesa , PPP 1609 .

Paratypes 6 specimens: Tortonian : Tuira FM , 3 specimens PPP 1137 ( NMB P15480-82 View Materials ); Yaviza FM , 1 specimen PPP 1566 ( NMB P15483 View Materials ). Messinian : Trinidad, Manzanilla FM , 2 specimens PPP 2666 ( NMB P15484-85 View Materials ) .

Referred material 5 specimens: Tortonian : Panama , 2 specimens same data as holotype; Yaviza FM , 1 specimen PPP 1566 . Messinian : Trinidad, Manzanilla FM , 2 specimens PPP 2666 .

Etymology Superlative of ornatus (Latin) = ornamented, referring to the strongly crenulated dorsal rim.

Diagnosis OL:OH = 1.0–1.1. Maximal size 2.35 mm (holotype). Predorsal rim high; postdorsal region distinctly higher. Dorsal rim strongly crenulated, with radial furrows extending on inner and outer faces. Sulcus narrow. Subcaudal iugum long, narrow.

Description Otolith size up to 2.35 mm in length (holotype). OH:OT = 3.0–3.2. Otolith shape rectangular with elevated postdorsal region, predorsal angle high, rounded, distinctly lower than postdorsal angle, postdorsal projection blunt, slightly longer than postventral angle, not bent outward. Ventral rim straight, horizontal, smooth or slightly undulating. Anterior and posterior rims nearly vertical; preventral angle blunt; posterior rim with distinct, mostly sharp indentation at its middle. All rims slightly undulating to strongly crenulated, particularly dorsal rim.

Inner face nearly flat in vertical direction, slightly bent in horizontal direction. Sulcus sole-shaped, narrow with low ostial lobe, slightly deepened, inclined at 10–15°. OL:SuL = 1.8–1.9 (rarely 2.1, Fig. 16f View Fig ). Subcaudal iugum long, relatively narrow. Dorsal depression wide, relatively short and moderately indistinct, with some radial furrows ingressing from the marginal crenulation, close to central portion of sulcus. Ventral furrow distinct, relatively close to ventral rim of otolith. Outer face distinctly convex, strongest inframedian, with several strong radial furrows related to marginal crenulation.

Discussion Bollmannia ornatissima is a relatively uncommon species in the Late Miocene of Pacific Panama (Darien) but has also been found in time-equivalent strata of Trinidad. Te specimens from Trinidad

( Fig. 16f–g View Fig ) differ from the Panamanian ones in the relatively short sulcus (OL:SuL = 1.9–2.1 vs 1.8–1.9), but we do not consider this difference as warranting separation on species level, particularly since the few Trinidadian specimens are also relatively small (OL = 1.3 mm and 1.45 mm in length).

Bollmannia ornatissima is best recognized by its intense marginal crenulation, particularly the dorsal rim, and the relatively narrow subcaudal iugum. It resembles B. nubila in the latter trait and the narrow sulcus but shows a much more pronounced postdorsal region. Bollmannia ornatissima differs from other species in the plexus such as B. marginalis and B. ocellata in the stronger crenulation of the dorsal rim, the narrower sulcus, and the narrower subcaudal iugum.