“Sharks are living fossils, perfectly adapted to rule the seas long before dinosaurs walked the land.” — National Geographic

https://www.youtube.com/watch?v=8Mtlgh3VdJQ&t=43s

Characteristics

Carcharhinus is a genus of requiem sharks within the family Carcharhinidae, characterized by the following notable features:

• Size: Species range from 1-3.5 meters (3-11.5 feet) in length, with the Oceanic Whitetip (C. longimanus) and Bull Shark (C. leucas) among the largest
• Body structure: Streamlined, torpedo-shaped bodies with powerful muscular systems optimized for continuous swimming
• Teeth: Most species possess serrated, triangular upper teeth designed for cutting and smooth-cusped lower teeth for gripping prey
• Fins: Typically have moderately sized first dorsal fins positioned over or slightly behind the pectoral fins
• Coloration: Generally gray to bronze dorsally, with lighter (often white) ventral surfaces, creating countershading camouflage
• Sensory system: Highly developed ampullae of Lorenzini for detecting electrical fields, plus excellent olfactory abilities
• Reproduction: Viviparous (live-bearing) with yolk-sac placenta, producing 2-20 pups per litter depending on species

Time Period

The Carcharhinus genus has a significant temporal range in Earth's history:

• First appearance: Fossil records date to the early Eocene epoch, approximately 56 million years ago

• Diversification: Major radiation occurred during the Miocene epoch (23-5.3 million years ago)

• Modern presence: Currently comprises approximately 35 recognized species, making it the largest genus of sharks

• Conservation status: Many species are vulnerable or endangered due to overfishing and habitat degradation