Austrolebias elongatus

Wilson J. E. M. Costa, 2006, The South American annual killifish genus Austrolebias (Teleostei: Cyprinodontiformes: Rivulidae): phylogenetic relationships, descriptive morphology and taxonomic revision., Zootaxa 1213, pp. 1-162 : 43

Clade A2: Austrolebias elongatus species group

Diagnosis

Distinguished from the remaining taxa within Austrolebias in possessing the following unambiguous synapomorphic features: scales absent above anal-fin base, at least in females; scales absent from anterior portion of frontal region; 2-3 supratemporal neuromasts; lachrymal curved along its dorso-ventral axis; lateral process of sphenotic robust, with an anterolateral pointed process; posterior arm of parasphenoid widened posteriorly; proximal portion of second epibranchial widened; second pharyngobranchial shortened; and pelvic bone reduced. Other synapomorphies of the A. elongatus species group include: approximately 50-75 scales in longitudinal series (except in A. wolterstorffi , with 31-35 scales, considered a reversion), and prominent contact organs on most pectoral-fin rays (a condition not present in A. wolterstorffi , parsimoniously interpreted as a reversal).