The Floreana Island Giant Tortoise was a subspecies of Galápagos tortoise endemic to Floreana Island in the Galápagos archipelago. These massive reptiles could reach over 1.5 meters (5 feet) in length and weigh up to 400 kg (880 lbs), making them among the largest tortoises to ever exist.

First documented by Charles Darwin during his visit in 1835, the tortoises were already rare due to exploitation by whalers and pirates who used them as a source of fresh meat on long voyages. The last known purebred individual died in captivity in 1852, though recent genetic studies have revealed hybrid descendants on other islands.

These tortoises played a crucial ecological role as "ecosystem engineers," shaping vegetation patterns through their grazing and dispersing seeds across the island. Their extinction dramatically altered Floreana's ecosystem.

The Floreana tortoise had several distinctive features:

• Size: Up to 1.5 m (5 ft) long and 400 kg (880 lbs)
• Shell: Saddleback shape allowing greater neck extension
• Lifespan: Potentially over 150 years in the wild
• Diet: Herbivorous - cacti, grasses, fruits and leaves
• Water storage: Could survive months without fresh water

The saddleback shell shape was an adaptation to reach higher vegetation in Floreana's drier environment. Their slow metabolism allowed them to survive long periods without food or water - an advantage that ironically made them ideal "living provisions" for sailors.

Current initiatives include:

• Genetic identification: Finding hybrids with Floreana ancestry
• Breeding programs: Attempting to "breed back" the subspecies
• Habitat restoration: Removing invasive species from Floreana
• Rewilding plans: Potential reintroduction of similar tortoises

In 2015, 19 tortoises with partial Floreana ancestry were identified on Isabela Island and moved to a breeding center, offering hope for partial restoration of this lost subspecies.

The Caribbean Monk Seal was the only seal species native to the Caribbean Sea and Gulf of Mexico. Growing to 2-2.4 meters (6.5-8 feet) long and weighing 160-270 kg (350-600 lbs), this marine mammal was the first New World mammal documented by Columbus in 1494, and the first seal species to go extinct due to human activities.

Once abundant throughout the Caribbean, the species declined rapidly due to hunting for its blubber (used for oil) and overfishing of its food sources. The last confirmed sighting was in 1952 at Serranilla Bank between Jamaica and Nicaragua, though unverified reports persisted into the 1970s.

This seal played an important role in Caribbean ecosystems as both predator and prey, maintaining fish populations and providing food for sharks. Its extinction represents a significant loss of marine biodiversity in the region.

The Caribbean Monk Seal had several distinctive features:

• Size: 2-2.4 m (6.5-8 ft) long, 160-270 kg (350-600 lbs)
• Coloration: Brownish or grayish with yellowish underside
• Head: Rounded with prominent whiskers
• Body: Streamlined with short front flippers
• Behavior: Docile and curious around humans

Unlike cold-water seals, it had a thinner blubber layer adapted to tropical waters. Historical accounts describe it as particularly sluggish on land, making it easy prey for hunters.

The seal's extinction affected Caribbean ecosystems by:

• Removing a key predator of reef fish and crustaceans
• Eliminating a food source for large sharks
• Disrupting nutrient cycling in coastal areas
• Creating an "empty niche" in marine food webs

Scientists speculate that some coral reef declines may be indirectly linked to the loss of this important predator that helped maintain balanced fish populations.