They are very buoyant and tend to float near the surface of the ocean to absorb natural sunlight. Phytoplankton are plants that get their energy through photosynthesis. There are 2 main types of marine plankton: The name plankton comes from the Greek word meaning 'drifter' and 'wanderer.' They have always played an integral role in the aquatic food web. Plankton are single-cell organisms that are carried along by the tides and currents of the ocean and are therefore known as marine drifters. This theory is known as the Alvarez hypothesis. This persistent winter frost ceased photosynthesis in plants and plankton. However, the asteroid itself is not what was so catastrophic for plant life it was the lingering winter as a result of the asteroid. The devastating effects of the asteroid diminished the supply of marine plankton so aggressively that scientists believe the ammonites could not survive. The primary food source for ammonites was marine plankton. This increased level of iridium metal is typical in asteroids but not Earth's crust. The soil and the clay found in this boundary contains levels of iridium that are surprisingly high. This event created a thin layer of sediment on marine and terrestrial rocks, and this partition is called the K-Pg boundary.

The Cretaceous-Paleogene event marked the end of the Mesozoic era and ushered in the beginning of our current era, the Cenozoic era. The most common tetrapods that survived are part of today’s sea turtle and crocodile families. These surviving four-limbed tetrapod creatures included mammals, reptiles, birds, and amphibians. This event decimated over three-quarters of all species on Earth and all but a handful of four-limbed animal species weighing more than 55 lbs. This mass extinction is referred to as the Cretaceous–Paleogene event. JHarnessing the Power of Healing CrystalsĪt the end of the Cretaceous period, a massive asteroid, estimated to be between 7-9 miles in diameter, hit Earth.JLow on Energy? These 5 Healing Crystals Can Help!.

Largest ammonite fossil