Steinmann-Institut, Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany.
Zoologisches Forschungsmuseum Alexander Koenig, Bonn, Germany.
PLoS One. 2023 Feb 1;18(2):e0280797. doi: 10.1371/journal.pone.0280797. eCollection 2023.
The platy limestone deposit of Vallecillo in northeastern Mexico is dated to the early-middle Turonian (Late Cretaceous) and known to contain a variety of well-preserved vertebrate fossils. One of the most common fish species is the teleost Tselfatia formosa. A review of 149 individuals reveals the presence of two types of body shapes (diamond-shaped and torpedo-shaped individuals) which is interpreted as sexual shape dimorphism (SSD). A unimodal size distribution illustrates a dominance of diamond-shaped specimens, but both body shape types are present in small (young) and big sized (old) individuals. The abundance of well-articulated and complete specimens suggests that T. formosa populated deep levels of the water column, which excluded buoyancy and flotation as well as carcass disintegration near the surface. The reconstruction of the dorsal and anal fins suggests the presence of a membrane between each fin ray and allows for ecological comparison of T. formosa with modern fan fishes.
墨西哥东北部瓦莱西略的层状石灰岩矿床的年代为早-中白垩世（晚白垩世），已知含有多种保存完好的脊椎动物化石。最常见的鱼类之一是 teleost Tselfatia formosa。对 149 个个体的研究表明，存在两种体型（菱形和鱼雷形个体），这被解释为性体型二态性（SSD）。单峰体型分布表明菱形标本占优势，但两种体型类型都存在于小（年轻）大和大（年老）个体中。大量关节良好和完整的标本表明，T. formosa 生活在水柱的深层，这排除了浮力和漂浮以及在靠近表面的地方的尸体分解。对背鳍和臀鳍的重建表明，每根鳍条之间存在一层膜，这使得可以将 T. formosa 与现代扇鱼进行生态比较。
