Sharks and rays (Chondrichthyes, Elasmobranchii) from the late Miocene Gatun Formation of Panama

Abstract

The late Miocene Gatun Formation of northern Panama contains a highly diverse and well sampled fossil marine assemblage that occupied a shallow-water embayment close to a purported connection between the Pacific and Atlantic (Caribbean) oceans. However, the diverse chondrichthyan fauna has been poorly documented. Based on recent field discoveries and further analysis of existing collections, the chondrichthyan fauna from this unit comprises at least 26 taxa, of which four species are extinct today. The remaining portion of the total chondrichthyan biodiversity has affinities with modern taxa and is therefore comprised of long-lived species. Based on known records of the modern geographic distribution range of the Gatun chondrichthyans, the fauna has mixed biogeographic affinities suggesting that around 10 million yr ago, a connection likely occurred between the Pacific Ocean and the Caribbean Sea. Given the known habitat preferences for modern chondrichthyans, the Gatun fauna was primarily adapted to shallow waters within the neritic zone. Finally, comparisons of Gatun dental measurements with other faunas suggest that many of the taxa have an abundance of small individuals, in agreement with previous studies that proposed this area as a paleonursery habitat for the species Carcharocles megalodon.

Late Miocene chondrichthyans from Lago Bayano, Panama: Functional diversity, environment and biogeography

“…Waite, 2016). This fauna is therefore Tortonian in age and correlative with the other important chondrichthyan-bearing units in Central and South America, including the Gatun Formation and Alajuela Formation of central Panama (Gillette, 1984;Pimiento et al, 2013a;MacFadden et al, 2017), Angostura Formation of Ecuador (Carrillo-Briceño et al, 2014), and upper Urumacro Formation of Venezuela (Carrillo-Briceño et al, 2015b).…”

Los peces (Chondrichthyes, Osteichthyes) del Plioceno inferior de Gran Canaria y Fuerteventura (Islas Canarias, España)

“…Late Miocene of Panama (Pimiento et al, 2013) Miocene and Pliocene of Morocco (Lecointre, 1952), Azores (Ávila et al, 2012), Europe (Reinecke et al, 2011), Africa (Antunes, 1978), American Atlantic and the Pacific, Ecuador (Carrillo-Briceño et al, 2014;Yabe et al, 2004).…”

A New Early Miocene (Aquitanian) Elasmobranchii Assemblage from the la Guajira Peninsula, Colombia

“…chubutensis, C. megalodon and the other species of the lineage has been debated over the years and hitherto there is no consensus among paleoichthyologists concerning the different taxonomical approaches that are still in use (e.g., Cappetta, 2012;Pimiento et al, 2010Pimiento et al, , 2013bReinecke et al, 2011;Bor et al, 2012). According to Pimiento et al (2013a), the teeth of sub-adult and adult specimens of C. megalodon during the late Miocene.…”

“…Additionally, the extinct Carcharocles and the carcharhiniform Hemipristis serra are commonly found in coastal assemblages (e.g., Pimiento et al, 2010Pimiento et al, , 2013bCappetta, 2012) but must have also been present in open oceanic depositional environments (Carrillo-Briceño et al, 2015). Their fossil record and cosmopolitan distribution (Cappetta, 2012) suggest that these large species were able to move along significant distances over oceanic basins.…”