Filling the gap: a fossil frogfish, genus Antennarius (Teleostei, Lophiiformes, Antennariidae), from the Miocene of Algeria G. Carnevale 1 & T. W. Pietsch 2 1 CNR – Istituto di Geoscienze e Georisorse and Dipartimento di Scienze della Terra, Universita di Pisa, Pisa, Italy 2 School of Aquatic and Fishery Sciences, College of Ocean and Fishery Sciences, University of Washington, Washington, USA Keywords Teleostei; Antennariidae; Antennarius monodi sp. nov.; fossil record; Miocene; Algeria. Correspondence Giorgio Carnevale, CNR – Istituto di Geoscienze e Georisorse, and Dipartimento di Scienze della Terra, Universita di Pisa, via S. Maria, 53, I-56126 Pisa, Italy. Email: carnevale@dst.unipi.it Received 31 August 2005; accepted 23 February 2006 doi:10.1111/j.1469-7998.2006.00163.x Abstract A new species of frogfish, Antennarius monodi sp. nov., is described from the Upper Miocene (Messinian) of Raz-el-Aı¨n, near Oran, north-east Algeria. The type and only specimen of this taxon is the first articulated skeleton belonging to the family Antennariidae ever recorded as a fossil. The morphological and meristic characters observed support the inclusion of this species in the Antennarius ocellatus group, where it shares several features with the extant Antennarius senegalensis. Morpho- logical features, sedimentary characters and faunal association concur to suggest that A. monodi sp. nov. possibly was a tropical, continental species that lived on muddy bottoms and turbid waters at depths less than 90–100 m. From a biogeo- graphic point of view, the presence of an antennariid closely related to A. senegalensis in the Late Miocene of the Mediterranean suggests that this area had strong biotic relationships with the eastern tropical Atlantic at that time. The integrative analysis of phylogenetic interrelationships and fossil record of the entire order Lophiiformes reveals that all the lophiiform lineages were already in existence in the Eocene. Moreover, the existence of a derived species of the genus Antennarius in the Late Miocene at last fills a large gap that exists in the fossil record of the Teleostei, suggesting that the modern antennariid body plan originated well before that period. Introduction Fossils offer unique information on evolution, providing the only evidence for the past existence of organisms that are now extinct, and giving calibrations of the minimum age of a determinate taxon. In addition, they often provide precise data on the order of events in phylogeny (e.g. Benton & Hitchin, 1996, 1997; Benton, 1998). The fossil record is clearly imperfect due to major sedimentary, systematic and taphonomic biases (see Smith, 2001), and fossil biodiversi- ties must be regarded as underestimates even when dealing with organisms with a hard skeleton and a long fossil record (Nebelsick, 1996). This is particularly true for the fossil record of teleost fishes, the quality of which depends mostly on ecological and sedimentary features of the depositional environments (e.g. algal blooms, anoxic bottoms, bacterial films, mass mortalities) that allow the preservation of articulated skeletal remains. Several groups of living teleosts are unrepresented as fossils, and for this reason their evolu- tionary history is completely unknown. Fishes of the order Lophiiformes are very rare in the fossil record. Except for a few Eocene fossils (see below), little information is available about the tempo and mode of evolution and diversification of these amazing fishes, thereby implying the existence of a very wide gap in the palaeontological history of this group. The purpose of this paper is to describe the first fossil skeletal remains of the family Antennariidae. The fossil was collected from the Upper Miocene (Messinian) diatomites of Raz-el-Aı¨n, near Oran, north-east Algeria (Arambourg, 1927), and has been found recently during the re-examina- tion (Carnevale, 2002, 2003, 2004a,b, 2006a,b) of the collec- tion of Miocene fishes from Algeria housed in the Muse´um national d’Histoire naturelle (MNHN) in Paris. Lophiiforms of the family Antennariidae, commonly referred to as frogfishes, are sedentary, shallow-water, marine fishes that spent most of their lives squatting on the bottom, maintaining the immobile, inert appearance of a sponge or coralline algae-encrusting rock (Pietsch, 1984a; Randall, 2005). The family Antennariidae includes about 40 species arranged in 13 genera that are abundant in sandy, eel-grass or rocky and coral reef habitats of all tropical oceans. Because of their highly cryptic habitus and amazing luring behaviour (Pietsch & Grobecker, 1978), these fishes are usually considered one of the most complex, efficient and well-documented cases of aggressive mimicry in the animal kingdom (see e.g. Luria, Gould & Singer, 1981). Nearly all the members of this family are voracious carni- vores characterized by extraordinary structural adaptations Journal of Zoology 270 (2006) 448–457 c  2006 The Authors. Journal compilation c  2006 The Zoological Society of London 448 Journal of Zoology. Print ISSN 0952-8369