Rare 鯨, クジラ fossil found in Panama clarifies evolution of sperm 鯨, クジラ 

Rare whale fossil found in Panama clarifies evolution of sperm whale

Almost since the time of Melville\'s epic hunt, scientists have been fascinated by the remarkable attributes of the sperm whale and its kin, the smaller pigmy and dwarf whales. Capable of diving to great depths and gifted with an acute sense of echolocation, these animals have remained inseparable from maritime lore. Scientists have now discovered a new species of an extinct pigmy sperm whale from Panama that clarifies key aspects of the evolution of the sperm whale.

This is the evolutionary tree of sperm whales, showing the relationships of extinct and living species, and when reduction of the spermaceti organ took place.

Credit: Natural History Museum of Los Angeles County

Almost since the time of Melville\'s epic hunt, scientists have been fascinated by the remarkable attributes of the sperm whale and its kin, the smaller pigmy and dwarf whales. Capable of diving to great depths and gifted with an acute sense of echolocation, these animals have remained inseparable from maritime lore.

An international team of scientists, led by the Natural History Museum of Los Angeles County\'s Curator of Marine Mammals Dr. Jorge Velez-Juarbe, has discovered a new species of an extinct pigmy sperm whale from Panama that clarifies key aspects of the evolution of these magnificent animals. The report published in the journal

  reveals an unexpected level of complexity in the evolution of the spermaceti of these whales, an organ located within the head that plays a key role in the generation of sound and in the whale\'s capacity for echolocation.

Whales, dolphins, and porpoises have a long fossil record, which documents the evolutionary journey from terrestrial ancestors to the fully marine organisms of today. Such a record has enabled scientists to better understand how changes in climate and continental distribution have transformed the marine ecosystems and the diversity life forms that they host. Yet, the poor fossil record of the smaller relatives of the well-known sperm whale, the 8- to 12-foot-long pigmy and dwarf sperm whales, has limited our understanding of the evolution of these mysterious animals.

Discovered and studied by a team of scientists from the NHM, Iowa State University, and the Smithsonian Tropical Research Institute, the new Panamanian fossil whale affords fresh evidence to this old problem.

"The new discovery gives us a better understanding of the ancient distribution of these poorly known relatives of the sperm whale," said Dr. Velez-Juarbe. "Previously we knew of similarly-aged pigmy and dwarf whales from Baja California and Peru, but this new fossil fills in an important geographic gap in the group\'s ancient distribution."

after the Isthmus of Panama, is known from the well-preserved skulls of two individuals, which remains were unearthed at a sea cliff along the Caribbean coast of Panama and from rock layers dated to about 7 million years ago. "Our study is part of a larger scientific effort aimed at understanding the changes in the marine habitats that resulted from the complete closure of the Isthmus of Panama," said Dr. Velez-Juarbe, referring to the separation between the eastern Pacific Ocean and the Caribbean Sea that took place sometime within the last 10 million years.

These rare fossils are among a handful other fossil whales known from Panama, where fossil hunting is often difficult due to the dense vegetation and thick soils that often covers the surface. Resurrected from their million-year-old entombment, the new fossils tell us that the evolution of characteristics related to sound emission and echolocation was far more complex than previously envisioned. The new study shows that at one time, these small sperm whales had a much larger spermaceti organ, which got downsized at least twice during the evolutionary history of these animals (including the evolutionary event that gave origin to the living pigmy and dwarf sperm whales). The reasons of this size reduction remain unclear; scientists would have to find more complete skeletons of Nanokogia and other closely related species to untangle the question. For now, Dr. Velez-Juarbe continues to explore the prehistoric seas of Central America--Captain Ahab would have been proud.

The above story is based on materials provided by Natural History Museum of Los Angeles County.

Jorge Velez-Juarbe , Aaron R. Wood, Carlos De Gracia, Austin J. W. Hendy. Evolutionary Patterns among Living and Fossil Kogiid Sperm Whales: Evidence from the Neogene of Central America.

Natural History Museum of Los Angeles County. "Rare whale fossil found in Panama clarifies evolution of sperm whale." ScienceDaily. ScienceDaily, 29 April 2015. <www.sciencedaily.com/releases/2015/04/150429145405.htm>.

Natural History Museum of Los Angeles County. (2015, April 29). Rare whale fossil found in Panama clarifies evolution of sperm whale.

Natural History Museum of Los Angeles County. "Rare whale fossil found in Panama clarifies evolution of sperm whale." ScienceDaily. www.sciencedaily.com/releases/2015/04/150429145405.htm (accessed April 30, 2015).

New Fossil Rattles Moby Dick\'s Family Tree

Salty Lakes and Signs of Life Under Antarctica

Apr. 29, 2015 — A pair of newly published papers lay out a method for outfitting birds with geolocators or radio transmitters that cuts precious weight from the package, allowing the devices to be used on very small ... read more

Illuminating the Dark Zone: Discoveries About a Specific Protein and Its Effects on Final Step of Cell Division

Apr. 29, 2015 — The human body is a cross between a factory and a construction zone -- at least on the cellular level. Certain proteins act as project managers, ... read more

Forest Canopies Buffer Against Climate Change

Apr. 29, 2015 — Current models of how forests will respond to climate change don\'t account for differences between adult and juvenile trees. Recent research of forest landscape ecology, finds that climatic buffering ... read more

Can Skull Shape and Function Determine What Kind of Food Was on Prehistoric Plates?

Apr. 29, 2015 — When paleontologists put together a life history for a long-extinct animal, it\'s common to infer the foods it ate by looking at modern animals with ... read more

Neural Circuit Involved in Combining Multiple Senses

Apr. 29, 2015 — Studying fruit fly larvae, scientists have mapped the entire neural circuit involved in combining vibration and pain sensations used in triggering an escape behavior. Combining information across ... read more

How the Lack of Specific Proteins Affects Development of Filamentous Fungi

Apr. 29, 2015 — Fungi can have a great economic impact. In industry, they are used as a source of enzymes or antibiotics. But they can also cause considerable economic damage as they are responsible for infections ... read more

How Does a Honeybee Queen Avoid Inbreeding in Her Colony?

Apr. 29, 2015 — Recombination, or crossing-over, occurs when sperm and egg cells are formed and segments of each chromosome pair are interchanged. This process plays an crucial role in the maintenance of genetic ... read more

Apr. 29, 2015 — Biophysicists are working toward an energy-landscape theory for chromosomes. The theory could help scientists understand the genomic roots of gene regulation, DNA replication and cell ... read more

Study Advances New Tool in the Fight Against Invasive Species

Apr. 29, 2015 — Asian carp. Burmese python. Hemlock woolly adelgid. These are just some of the most destructive pests and the world\'s worst invasive species that raise the hackles of fisherman, farmers, and wildlife ... read more

Ancient Clam Beaches Not So Natural, Study Shows

Apr. 29, 2015 — Ancient coastal Indigenous people were more than hunter-gatherers, new research shows. Researchers suggest that the Pacific Northwest is one of the few places in the world where it can be documented\' ... read more

Skull, Ancestors, Help Identify Prehistoric Diet

How A 7-Year-Old Helped Find A Brand New Group Of Dinosaurs

Baby Elephant Rescued from Well by Villagers in India

  Print   Email   Share

Tracking Sperm Whales\' Ecology Through Stomach Contents

Giant Squids\' Giant Eyes: The Better to See Hungry Whales With

Whales Have Accents and Regional Dialects: Biologists Interpret the Language of Sperm Whales

Giant Sperm Whale from the Miocene Period Discovered in Peru

Elderly Crickets Are Set in Their Ways, Study Finds

Salty Aquifer, Previously Unknown Microbial Habitat Discovered Under Antarctica

Rubber from Dandelions: Key Components in Formation of Rubber Identified

Human Hunting Weapons May Not Have Caused the Demise of the Neanderthals

Origin of Life: Chemistry of Seabed\'s Hot Vents Could Explain Emergence of Life

3-D Image of Live Embryo Turning Itself Inside out

Could Smell Hold the Key to Limiting or Ending Pesticide Use?

Dive Discovers Missing Aircraft Hangar of Sunken WW II-Era Japanese Submarine

Looking to Fossils to Predict Tooth Evolution in Rodents: Ever-Growing Molars in the Future?

Entire Genomes of Woolly Mammoths Mapped: Clues to Extinction, Possibility of Bringing Mammoths Back

Stegosaurus Plates May Have Differed Between Male, Female

U.S. Air Force plans to launch 1990s-built weather satellite

Hands free talk with global reach and style

A pigeon-size dinosaur with bat wings? Strange but true

Russia abandons supply mission to International Space Station

More efforts needed to raise teen long-term contraceptive use

FDA panel recommends approval for Amgen\'s skin cancer immunotherapy

Saudi Arabia bans poultry meat from Canadian province Ontario

Health literacy important for heart failure patient survival

FDA could approve drugs for new uses on less data: draft law

China solar expansion needs billions from wary investors

JV of McDonald\'s fries supplier fined in China for water pollution: Xinhua

Map, video plot activities of bears living among humans in Anchorage

McConnell suggests Obama plan to cut power emissions won\'t stick

Property portal Zoopla buys price comparison site uSwitch

Sony sees FY profit surging on camera sensor sales, cost cuts

Tattoo snafu irks inked Apple Watch wearers

Nokia downplays shareholder opposition to Alcatel-Lucent deal

Abe, seeking new spark for Japan high-tech, heads to Silicon Valley