A feature commonly overlooked in most descriptions of the thylacine is the whitish blaze to its chest.  This originates from between the front legs and extends as far as the neck.     The characteristic stripe pattern of the thylacine is shared with only four other living species of mammals: the numbat (Myrmecobius fasciatus), Banded hare wallaby (Lagostrophus fasciatus), Banded palm civet (Hemigalus derbyanus), and Zebra duiker (Cephalophus zebra) (Renshaw 1938).  A comparison between the stripe patterns of the thylacine and Zebra duiker can be viewed here. Sexual dimorphism:     In the course of the thylacine's evolution, both intraspecific and intersexual competition occurred, and this is responsible for the sexual dimorphism in the species.  It was J. West (1852) who first noticed this disparity: "females are smaller and more agile".     Intraspecific competition occurs when members of the same species vie for the same resources in an ecosystem.  The consequence of this enduring intraspecific competition in the thylacine . Last known captive thylacine showing chest blaze. Beaumaris Zoo (QD) Hobart (1933). Photo courtesy: David Fleay Trustees. .

is as a result of the available prey resources.  The thylacine's smaller prey species (potoroos, bettongs, placental mice, small dasyurids, bandicoots, lizards and birds) are good sprinters and are likely to be the main prey of the smaller and more agile females.  The "big game", such as the large Forester kangaroo, wombat and the Red-necked wallaby however, can only be overwhelmed by the larger, stronger, but not so agile males.  This sharing of the available prey resources has two distinct advantages:

    1.  A wider reaching palette of animals can be procured by one species with two specialised sexual partners. 

    2.  The second advantage is seasonal; in periods when prey resources are scarce, a high percentage of a population can avoid intraspecific competition. 

    It is highly likely that male size is directly related to intrasexual competition for access to oestrus females; hence why males become older and larger before they get the opportunity to reproduce.  Charles Darwin (1859), in his book: "On the Origin of Species", states:

    "And this leads me to say a few words on what I call Sexual Selection.  This depends, not on a struggle for existence, but on a struggle between the males for possession of the females; the result is not death to the unsuccessful competitor, but few or no offspring".

    Most of the available historical literature seems to suggest that an adult thylacine has a total body length (inclusive of the tail) of between 1.4m [55 inches] and 1.6m [62 inches], with the animal standing at around 60cm [24 inches] at the shoulder.

    G. P. Harris (1808), in his paper: "Description of two new Species of Didelphis from Van Diemen's Land", published in the Transactions of the Linnean Society of London, makes reference to the body measurements of the type specimen: "The length of this animal from the tip of the nose to the end of the tail is 5 feet 10 inches (177.8 cm), of which the tail is about 2 feet (60.96cm)".

    Edwards Crisp (1855) published a paper in the Proceedings of the Zoological Society of London in which he compared the anatomy of the thylacine with that of the Cape hunting dog (Lycaon pictus).  Crisp notes that his specimen measured some 85 cm (2 ft. 9½ in.) from nose to base of the tail, with a tail length of 38 cm (15 in.).

   In the project summary to the 5th revision of the International Thylacine Specimen Database (Sleightholme & Ayliffe 2013), there are several historical references to the body measurements of thylacines.  These were sourced from articles in the Tasmanian press.

    In the Mercury newspaper of the 15th November 1889 (p. 3), it is stated: 

    "Last week two miners at the Twilight succeeded in killing a fine native tiger.  It was caught in a snare, but on the approach of Messrs. George Ward and J. Smith it broke away, but was soon overhauled by a kangaroo dog.  A grand tussle ensued, but the tiger was handicapped by receiving the contents of four discharges from a gun, and after a game struggle killed.  It measured 6ft. from the nose to the tip of the tail, 3ft in girth, and 2ft. 9in. high, and although the teeth were quite competent to do any amount of damage amongst Messrs. McKenzie's and Hewitt's flocks, their worn appearance testified to its great age.  The head and paws were taken to Fingal to claim the Government reward".

    The Adelaide Register dated 10th June 1904 (p. 4) reports: 

    "Recently as Mr. H. Turner, of Cluan, on the outskirts of the Glenore district, was going round his traps, he was surprised to find a large native tiger caught by the toes of one hind foot (says The Launceston Examiner).  Mr. Turner was about to secure his prey, when the trap chain broke, but, being an active man, he managed after a stiff chase to get hold of his quarry by the tail, and, protecting himself with a stick, got the animal into a large bag, which he fortunately had with him.  The tiger measures about 5 ft. 4 in. from tip to tip, and its captor has it chained up dog-fashion.  It sulked for a couple of days, but then took to its food all right.  Mr. Turner values his capture at £5".