A digit is one of several most distal parts of a limb , such as fingers or toes , present in many vertebrates .
19-466: [REDACTED] Look up digit or digits in Wiktionary, the free dictionary. Digit may refer to: Mathematics and science [ edit ] Numerical digit , as used in mathematics or computer science Hindu–Arabic numerals , the most common modern representation of numerical digits Digit (anatomy) , the most distal part of
38-470: A 2008 study by Boisvert et al. determined that this was mistaken. They discovered that the final bony portion of the fin in Panderichthys is split into at least four fin radials, bones similar to rudimentary fingers. Thus, in the evolution of tetrapods a shift occurred where the outermost rays of the fins were lost and replaced by the inner radials, which evolve into the earliest digits. This change
57-486: A character in the TV series Cyberchase Digit (EP) , by Echobelly, 2000 Digit (magazine) , an Indian information technology magazine Liquid and digits , a type of gestural, interpretive, rave and urban street dance See also [ edit ] Dig It (disambiguation) Digital (disambiguation) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with
76-438: A character in the TV series Cyberchase Digit (EP) , by Echobelly, 2000 Digit (magazine) , an Indian information technology magazine Liquid and digits , a type of gestural, interpretive, rave and urban street dance See also [ edit ] Dig It (disambiguation) Digital (disambiguation) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with
95-553: A finger or toe Digit (unit) , an ancient measurement unit Hartley (unit) or decimal digit, a unit of information entropy Personalities [ edit ] Digit, a gorilla studied by Dian Fossey , killed by poachers and buried near Fossey's grave Digit Fund , now the Dian Fossey Gorilla Fund International, founded by Fossey to raise money for anti-poaching patrols Arts and media [ edit ] Digit ( Cyberchase ) ,
114-473: A limb, such as a finger or toe Digit (unit) , an ancient measurement unit Hartley (unit) or decimal digit, a unit of information entropy Personalities [ edit ] Digit, a gorilla studied by Dian Fossey , killed by poachers and buried near Fossey's grave Digit Fund , now the Dian Fossey Gorilla Fund International, founded by Fossey to raise money for anti-poaching patrols Arts and media [ edit ] Digit ( Cyberchase ) ,
133-526: A more useful hand. Surgeons did this at the Institute of Reconstructive Plastic Surgery in New York to a 32-year-old man with the initials O. G.. They touched O. G.’s fingers before and after surgery while using MRI brain scans. Before the surgery, the fingers mapped onto his brain were fused close together; afterward, the maps of his individual fingers did indeed separate and take the layout corresponding to
152-401: A mutation can be surgically corrected, and whether such correction is indicated, is case-dependent. For instance the former chess world champion Mikhail Tal lived all his life with only three right-hand fingers. Each finger has an orderly somatotopic representation on the cerebral cortex in the somatosensory cortex area 3b, part of area 1 and a distributed, overlapping representation in
171-478: A normal hand. Two ideas about the homology of arms, hands, and digits exist. Until recently, few transitional forms were known to elaborate on this transition. One particular example is Panderichthys , a coastal fish from the Devonian period 385 million years ago. Prior to 2008, Panderichthys was interpreted as having a fin terminating at a single large plate surrounded by lepidotrichia (fin rays). However,
190-418: Is closer to tetrapods than Tiktaalik . At any rate, it demonstrates that the fish–tetrapod transition was accompanied by significant character incongruence in functionally important structures." Digit-like radials are also known in the rhizodont fish Sauripterus , though this is likely a case of convergent evolution. Elpistostege , a tetrapodomorph fish closely related to Tiktaalik , preserves one of
209-490: Is consistent with additional evidence from the embryology of actinopterygians , sharks and lungfish . Pre-existing distal radials in these modern fish develop in a very similar way to the digits of tetrapods. Several rows of digit-like distal fin radials are present in Tiktaalik , a much more complete Devonian vertebrate described in 2006. Though frequently described as the missing link between fishes and tetrapods,
SECTION 10
#1732794609892228-416: The supplementary motor area and primary motor area . The somatosensory cortex representation of the hand is a dynamic reflection of the fingers on the external hand: in syndactyly people have a clubhand of webbed, shortened fingers. However, not only are the fingers of their hands fused, but the cortical maps of their individual fingers also form a club hand. The fingers can be surgically divided to make
247-484: The exact relationship between Panderichthys , Tiktaalik , and tetrapods are yet to be fully resolved. Tiktaalik had some features of the forefin more similar to earlier fish, such as a large ulnare and a distinct axis of larger bones down the middle of the fin. According to Boisvert et al. (2008), "It is difficult to say whether this character distribution implies that Tiktaalik is autapomorphic , that Panderichthys and tetrapods are convergent, or that Panderichthys
266-407: The 💕 [REDACTED] Look up digit or digits in Wiktionary, the free dictionary. Digit may refer to: Mathematics and science [ edit ] Numerical digit , as used in mathematics or computer science Hindu–Arabic numerals , the most common modern representation of numerical digits Digit (anatomy) , the most distal part of a limb, such as
285-462: The hand" or "digit of the foot" instead. In Japanese , yubi (指) can mean either, depending on context. Humans normally have five digits on each extremity. Each digit is formed by several bones called phalanges , surrounded by soft tissue. Human fingers normally have a nail at the distal phalanx. The phenomenon of polydactyly occurs when extra digits are present; fewer digits than normal are also possible, for instance in ectrodactyly . Whether such
304-399: The most tetrapod-like hands in any prehistoric fish. The hand of Elpisostege had 19 distal fin radials arranged into blocks up to four radials long. These sequential blocks of radials are very similar to digits. Birds and theropod dinosaurs (from which birds evolved) have three digits on their hands. Paradoxically the two digits that are missing are different: the bird hand (embedded in
323-449: The title Digit . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Digit&oldid=1218236107 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages digit From Misplaced Pages,
342-852: The title Digit . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Digit&oldid=1218236107 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Digit (anatomy) Some languages have different names for hand and foot digits (English: respectively " finger " and " toe ", German: "Finger" and "Zeh", French: "doigt" and "orteil"). In other languages, e.g. Arabic , Russian , Polish , Spanish , Portuguese , Italian , Czech , Tagalog , Turkish , Bulgarian , and Persian , there are no specific one-word names for fingers and toes; these are called "digit of
361-527: The wing) is thought to derive from the second, third and fourth digits of the ancestral five-digit hand. In contrast, the theropod dinosaurs seem to have the first, second and third digits. Recently a Jurassic theropod intermediate fossil Limusaurus has been found in the Junggar Basin in western China that has a complex mix: it has a first digit stub and full second, third and fourth digits but its wrist bones are like those that are associated with
#891108