Theby Andrew Blitman Evolution of billfish

First appearance and last appearance of billfish species in relation to the geologic timescale, the evolution of the Caribbean, and the closing of the Tethys Ocean. Note the 10-million-year gap in the Miocene (Taken from Fierstine 2006)

and perhaps most interesting, the ability to enormous fish, giant squids, and massive warm the temperature of certain muscles marine reptiles. However, a mass Photo courtesy of Chris Donato. and organs. However, research into these extinction wiped out most of the colossal two families of fish has shown that billfish creatures that dominated the Cretaceous If you were to ask any sportfisherman (Istiophoridae and Xiphiidae) and tuna seas. Fortunately, when it comes to what they think is the most challenging, (Scombridae) have taken very different evolution the extinction of one species is hardest fighting, and most awe inspiring evolutionary paths to become the apex an opportunity for another. This was the fish in the sea and there is a good chance predators they are today. While knowledge case for billfish, which first appeared in that their response will be either a billfish of billfish evolution is sparse, more than the fossil record during the period that or tuna species. Ask any marine biologist enough information exists to piece followed, the Paleocene. the same question and they too would together a story that can positively affect likely agree. Both billfish and tuna are the conservation movement. The earliest fossils of billfish were found known to migrate thousands of miles, in Turkmenistan about ten years ago

grow to well over a thousand pounds, and Fossils from North America, Europe, and belong to the species, Hemingwaya share many of the same prey species. and Russia suggest that the earliest sarissa, appropriately named after the Both have evolved similar adaptations Scombroids evolved during the late author whose books first made billfish to thrive in the open ocean including Cretaceous Period about 70 million years famous. Spanning only a foot in length, streamlined body shapes, large fins to ago. At this time, the Earth was lush these small fish were long, slender, and propel them effortlessly through the water, and tropical and seas that teemed with streamlined resembling a cross between

Aglyptorhynchus, from Fierstine 2006 Xiphiorhynchus, from Fierstine 2006 Hemingwaya, From Fierstine 2006 6