Ellimmichthys longicostatus ( Cope, 1886 )

Alvarado-Ortega, Jesús, Than-Marchese, Bruno Andrés & Melgarejo-Damián, Pilar, 2020, On the Albian occurrence of Armigatus (Teleostei, Clupeomorpha) in America, a new species from the Tlayúa Lagerstätte, Mexico, Palaeontologia Electronica (a 52) 23 (3), pp. 1-30 : 19-20

Ellimmichthys longicostatus ( Cope, 1886) .

Ellimmichthys goodi Eastman, 1912 . Hauterivian-Barremian. Recôncavo Fm., Brazil.

Aptian-Albian. Cocobeach Series, Equatorial Guinea.

Ellimmichthys maceioensis Malabarba, Do Carmo, Gómez-Pérez, and Aptian-Albian. Maceio Fm. , Brazil. Queiroz-Neto, 2004.

Eoellimmichthys superstes Marramà, Bannikov, Kriwet, and Carnevale, Early Eocene. Pesciara , Italy. 2019.

Ezkutuberezi carmenae (Poyato-Ariza, López-Horgue, and García- Valanginian-Barremian. Villaro Fm., Spain.

Garmilla, 2000).

Foreyclupea loonensis Vernygora, Murray and Wilson, 2016 .

members of the unnatural ellimmichthyiform group composed of double-armored herrings. In these fishes, the predorsal scutes show distinctive features, often with diagnostic value ( Grande, 1982, 1985; Chang and Grande, 1997, Chang and Maisey, 2003; among others). The predorsal scutes of A. carrenoae and A. brevissimus are subtriangular or heart-shaped, have smooth borders, and exhibit inconspicuous superficial ornamentation. In Ellimma , Ellimmichthys , Triplomystus , and Tycheroichthys these scutes are more laterally expanded, becoming subrectangular, preserve the smooth borders, and are strongly ornamented with ridges and tubercles. In Diplomystus the predorsal scutes are highly distinctive; these are subrectangular, antero-posteriorly shorth and extremely lat-

Albian. Loon River Fm., Canada.

erally expanded, smooth, and have a strongly serrated posterior border. Other genera show predorsal scutes with different combinations of these features, as in Sorbinichthys , Kwangoclupea , and Tunisiaclupea (e.g., Taverne, 1997; Bannikov and Bacchia, 2000; Murray and Wilson, 2011; Boukhalfa et al., 2019). As Grande (1982, 1985) stated, Armigatus differs from other ellimmichthyiforms in the presence of an incomplete predorsal scute series. Armigatus carrenoae sp. nov. shares this feature ( Figure 10 ).

Armigatus was erected by Grande (1982, p. 4), based on a single species, A. brevissimus ( Figures 1 , 12 ) and its original diagnosis included the following features: 1) the osteoglossid-like tooth patch on the parasphenoid; 2) the parietals are in

Species Age and Distribution

Gateroclupea branisai Signeux, 1964 (see Marramà and Carnevale, Late Cretaceous-Paleocene. Cayara, Bolivia.

2017)

Horseshoeichthys armaserratus Newbrey, Murray, Brinkman, Wilson, Maastrichtian. Horseshoe Canyon Fm. , Canada.

and Neuman, 2010.

Figures

FIGURE 1. Specimen IGM 11532, Armigatus brevissimus from the Cenomanian shallow marine deposits of Hekel, Lebanon, coated with magnesium smoke.

FIGURE 10. Predorsal scutes series of A. carrenoae sp. nov. from Tlayúa. A, closeup of the predorsal region of IGM 11536 (inverted for comparative purposes). B, closeup of predorsal region of IGM 11537. C, idealized drawing of B. Abbreviations: afr, anal fin ray; pd, predorsal bone; pds, predorsal scutes; dppt, dorsal proximal pterygiophore; upds, unmodified predorsal scales.

FIGURE 12. Dorsal region of Armigatus brevissimus. A, closeup of the specimen IGM 11532 from the Cenomanian shallow marine deposits of Hekel, Lebanon, under white light. B, idealized and simplified drawing of predorsal scutes and near bones based on A. Abbreviations: afr, anal fin ray; pd, predorsal bone; pds, predorsal scutes; dppt, dorsal proximal pterygiophore; upds, unmodified predorsal scales.