FOSSIL BATS OF THE AMERICAS
Natalidae: [phylogeny for this family]
Type Specimen: Florida Museum of Natural History UF 108641, partial right dentary with m1-m3. [[image ] holotype specimen and detail of teeth, Thomas Farm, Florida]
Type Locality and Horizon: Thomas Farm local fauna, NE of Bell, Gilchrist County, Florida, USA; early Miocene (early Hemingfordian); Miocene clays and sands infilling a paleokarst sinkhole developed within Eocene marine limestone.
Diagnosis (from Morgan and Czaplewski 2003): Mandibular ramus is deep below molars. Ventral margin of mandible is straight between p4 and mandibular angle. Summit of coronoid process of mandible is comparatively well developed with triangular-shaped dorsal tip. Anterior edge of coronoid process curves posterodorsally from alveolar margin to dorsal tip of coronoid at an angle of about 70°. Coronoid process rises above level of articular condyle. Posterior portion of coronoid process slopes ventrally from tip of coronoid down to condyle. Distinct mandibular angle is present directly ventral to tip of coronoid. Base of angular process is located halfway between ventral edge of mandible and alveolar margin in vertical dimension and about halfway between coronoid and condyle in anteroposterior dimension. Angular process does not flare strongly laterally. Mandibular foramen opens level with alveolar margin. Two features, the comparatively well developed triangular-shaped coronoid process that is taller than the articular condyle and the ventral position of the mandibular foramen and angular process, reflect a lesser degree of dorsal cranial flexion in Primonatalus than in Natalus. Posterior mental foramen located in deep concavity near alveolar margin between roots of c1 and p2. The p3 is larger, longer, and more compressed with distinct concavity posterior to main cusp. Metaconid and entoconid same height on m1 and m2. Carnassial-like notches on cristid obliqua and postcristid on lower molars present but weak. Lophid associated with carnassial-like notch extending posteriorly from cristid obliqua into talonid basin absent. Talonid notch was deeper than in Recent natalids because of taller metaconid and more ventral connection of entocristid to trigonid. Cristid obliqua also connects to trigonid more ventrally. Labial cingular cusp of P4 is low. Occlusal outline of P4 has anterior indentation. Talon weakly developed on M1-M2. Lingual cingulum weak on upper molars. Humerus has broad triangular-shaped epitrochlea with no notch between weak medial process and distal spinous process. Distal spinous process small, projecting only to edge of trochlea or very slightly distal to it, and separated from trochlea by narrow but distinct notch.
Natalidae, genus and species indet.
I-75 local fauna, near Gainesville, Alachua County, Florida, USA; early Oligocene (late Whitneyan); Oligocene clays infilling a small paleokarst solution cavity developed within marine Eocene limestone (Morgan and Czaplewski 2003).