Echolocation, also called bio sonar, is a biological active sonar used by several animal groups, both in the air and underwater. Echolocating animals emit calls and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects. Echolocation is used for navigation, foraging, and hunting prey.
Microbats constitute the suborder Microchiroptera within the order Chiroptera (bats). Bats have long been differentiated into Megachiroptera (megabats) and Microchiroptera, based on their size, the use of echolocation by the Microchiroptera and other features; molecular evidence suggests a somewhat different subdivision, as the microbats have been shown to be a paraphyletic group.
Megabats constitute the family Pteropodidae of the order Chiroptera (bats). They are also called fruit bats, Old World fruit bats, or—especially the genera Acerodon and Pteropus—flying foxes. They are the only member of the superfamily Pteropodoidea, which is one of two superfamilies in the suborder Yinpterochiroptera. Internal divisions of Pteropodidae have varied since subfamilies were first proposed in 1917. From three subfamilies in the 1917 classification, six are now recognized, along with various tribes. As of 2018, 197 species of megabat had been described.
The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River in Colorado, Wyoming, and Utah. The sediments are deposited in very fine layers, a dark layer during the growing season and a light-hue inorganic layer in the dry season. Each pair of layers is called a varve and represents one year. The sediments of the Green River Formation present a continuous record of six million years. The mean thickness of a varve here is 0.18 mm, with a minimum thickness of 0.014 mm and maximum of 9.8 mm.
Icaronycteris is an extinct genus of microchiropteran (echolocating) bat that lived in the early Eocene, approximately 52.2 million years ago, making it the earliest bat genus known from complete skeletons, and the earliest known bat from North America. Multiple exceptionally preserved specimens, among the best preserved bat fossils, are known from the Green River Formation of North America. The best known species is I. index. Fragmentary material from France has also been tentatively placed within Icaronycteris as the second species I. menui. I. sigei is based on well-preserved fragments of dentaries and lower teeth found in Western India. In 2023, the species I. gunnelli also from the Green River Formation was distinguished from I. index, and I. menui and I. sigei were proposed to be removed from the genus due to them not being closely related.
Palaeochiropteryx is an extinct genus of bat from the Middle Eocene of Europe and North America. It contains three very similar species – Palaeochiropteryx tupaiodon and Palaeochiropteryx spiegeli, both from the famous Messel Pit of Germany, as well as Palaeochiropteryx sambuceus from the Sheep Pass Formation. They are usually found complete and exceptionally preserved, even retaining the outlines of their fur, ears, and wing membranes.
In evolutionary biology, the flying primate hypothesis is that megabats, a subgroup of Chiroptera, form an evolutionary sister group of primates. The hypothesis began with Carl Linnaeus in 1758, and was again advanced by J.D. Smith in 1980. It was proposed in its modern form by Australian neuroscientist Jack Pettigrew in 1986 after he discovered that the connections between the retina and the superior colliculus in the megabat Pteropus were organized in the same way found in primates, and purportedly different from all other mammals. This was followed up by a longer study published in 1989, in which this was supported by the analysis of many other brain and body characteristics. Pettigrew suggested that flying foxes, colugos, and primates were all descendants of the same group of early arboreal mammals. The megabat flight and the colugo gliding could be both seen as locomotory adaptations to a life high above the ground.
The calcar, also known as the calcaneum, is the name given to a spur of cartilage arising from inner side of ankle and running along part of outer interfemoral membrane in bats, as well as to a similar spur on the legs of some arthropods.
Archaeonycteris is an archaic bat genus whose fossilised remains have been found in Germany, France, England and India.
Australonycteris is an extinct and monotypic genus of microchiropteran bat with the single species Australonycteris clarkae. The species is known from fragmentary remains found at the Murgon fossil site, in south-eastern Queensland, dating to the early Eocene, 54.6 million years ago. It is the oldest bat from the Southern Hemisphere and one of the oldest bats in the world, and inhabited forests and swampy areas, with a diet of insects and possibly small fish.
Bats are flying mammals of the order Chiroptera. With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out digits covered with a thin membrane or patagium. The smallest bat, and arguably the smallest extant mammal, is Kitti's hog-nosed bat, which is 29–34 millimetres in length, 150 mm (6 in) across the wings and 2–2.6 g in mass. The largest bats are the flying foxes, with the giant golden-crowned flying fox reaching a weight of 1.6 kg and having a wingspan of 1.7 m.
Karanisia is an extinct genus of strepsirrhine primate from middle Eocene deposits in Egypt.
Palaeochiropterygidae is a family of extinct bats. It was originally erected by the Swiss naturalist Pierre Revilliod in 1917 after discoveries of Palaeochiropteryx fossils from the Messel Pit of Germany. Palaeochiropterygidae was merged into Archaeonycteridae by Kurten and Anderson in 1980, but modern authorities specializing in bat fossils maintain the distinction between the two. It was classified to the unranked clade Microchiropteramorpha by Smith et al. in 2007.
Echolocation systems of animals, like human radar systems, are susceptible to interference known as echolocation jamming or sonar jamming. Jamming occurs when non-target sounds interfere with target echoes. Jamming can be purposeful or inadvertent, and can be caused by the echolocation system itself, other echolocating animals, prey, or humans. Echolocating animals have evolved to minimize jamming, however; echolocation avoidance behaviors are not always successful.
Necromantis is an extinct genus of bat that lived during the Eocene. Its fossils are found in the Quercy Phosphorites Formation of France and the Djebel Chambi in Tunisia. Specimens of Necromantis are notable for their large size and specialization towards a predatory lifestyle.
Matthesia was a primitive bat genus in the family Palaeochiropterygidae. Matthesia is represented by two species known from the middle Lutetian of Geiseltal, Germany. It may be a junior synonym of Palaeochiropteryx.
Bats are the only mammal capable of true flight. Bats use flight for capturing prey, breeding, avoiding predators, and long-distance migration. Bat wing morphology is often highly specialized to the needs of the species.
Onychonycteridae is an extinct family of bats known only from the early Eocene of Europe and North America. The type species, Onychonycteris finneyi, was described in 2008 from two nearly complete skeletons found in the Green River Formation of southwestern Wyoming. Since that time a number of previously described fossil bat species have been assigned to Onychonycteridae, as well as two more recently discovered species.
Hassianycteris is an extinct genus of Early Eocene (Ypresian) to Middle Eocene (Lutetian) bats from the Hassianycterididae with four or five known species: the type, H. magna, and H. revilliodi, all found in the Messel pit, Germany, H. kumari, found in the Cambay Shale Formation, India, and the possible fifth species "H." joeli, found in the Kortijk Clay Formation, Belgium, which may instead belong to Onychonycteridae. The Messel bats Palaeochiropteryx and Hassianycteris are the first fossil mammals whose colouration has been discovered: both were reddish-brown when alive.
