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 (trī-dăk′təl) also tri·dac·ty·lous (-tə-ləs)
adj. Zoology
Having three digits on each extremity.

[Greek tridaktulos, three-fingered : tri-, tri-; see trei- in Indo-European roots + daktulos, finger.]

tri·dac′ty·ly (-tə-lē) n.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(traɪˈdæktəl) or


(Anatomy) having three digits on one hand or foot
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
Over time, the three species shifted from tridactyl to monodactyl distal limb anatomy, with the third metacarpal becoming prominent.
(2015) describe small tridactyl footprints from a new Lower Cretaceous dinosaur tracksite of La Rioja.
Atreipus acadianus was produced by a habitually quadrupedal tetrapod with a tridactyl pes and a functionally tetradactyl manus.
The hipparionine horses are with an isolated protCone on maxillary premolar and molar teeth and, as far as known, tridactyl feet, including genera: Cormohipparion, Neohipparion, Nannippus, Pseudhipparion, Hipparion (North American genus), Hippotherium, Cremohipparion, Hipparion, Sivalhippus, Eurygnathohippus (= senior synonym of Stylohipparion), Proboscidipparion, Plesiohipparion (Wolf et al., 2013).A significant size difference has been noted by many authors in dental and metapodial dimensions between the two supraspecific hipparionine groups of the Siwaliks: Sivalhippus and Cremohipparion (e.g.
On the placentation of the tridactyl sloth (Bradypus griseus) with a description of the characters of the fetus.
The dinosaur's footprints usually toe slightly inward (slightly negative footprint rotation), as is typical of Comanchean tridactyl footprints attributed to theropods (Farlow 1987).
Diagnosis: A large hipparion with tridactyl feet and deep preorbital facial fossa separated from the orbit by a relatively wide preorbital bar, fossa deeply pocketed posteriorly, medially deep and with a well defined continues peripheral border including the anterior rum, cheek teeth complexly ornamented with thickly banded fossette plications and bifid to trifid plicaballins, protocones distinctly flattened lingually and rounded labially, hypoglyphs deeply incised, P2 anterostyle elongate (Colbert, 1935; Ghaffar, 2005).
The photogrammetric images (Falkingham, 2012) were obtained using Agisoft PhotoScan[TM] (version software (Grupo Aragosaurus, Universidad de Zaragoza License) both for quadruped and tridactyl tracks with the aim of studying the track morphology through depth maps and contour lines.
DESCRIPTION: Small bipedal, tridactyl, right theropod pes impression preserved in convex hyporelief, 7 cm long and 4.6 cm wide.
Two parallel tridactyl trackways are preserved, indicating a direction of movement of 182[degrees].