The External Anatomy
of the Thylacine
Robert Paddle (2000,
p. 4), in his book: "The Last Tasmanian Tiger", quotes an average
direct length for an adult male thylacine as 1.63m, and an adult female
as 1.54m. The average male body length measurement as cited by Paddle
is consistent with the sample group. The average body length measurement
for females however, is some 11% greater than the sample group.
Regarding tail length
in relation to overall body length, Moeller (1968) notes that: "The
tail ranges from 40% to 60% of the head body length". From the
sample of 18 males, the tail length averaged 43.1% of the nose-to-root-of-tail
measure, and from the sample of 9 females, the tail length averaged 45.3%.
These figures are consistent with the lower range
quoted by Moeller.
A graphical comparison
of the mean body measurements (mm) of adult thylacines.
Source: Dr. Stephen Sleightholme.
Male thylacine body
length measurements (mm). Source: Dr. Stephen Sleightholme.
blue portions of the columns represent nose-to-root-of-tail measurement,
and the contrasting darker shade the tail
length. The three juvenile specimens are shown in contrasting shades
of green. The Cambridge Museum of Zoology
skin specimen A6 7.4 has a withered tail, and the yellow
column base denotes this. All imperial measurements have been converted
to centimetres at 2.54cm to 1 inch.
Body weight (mass):
Female thylacine body
measurements (mm) taken from 10 specimens. Source: Dr. Stephen Sleightholme.
red is the nose-to-root-of-tail measurement, and contrasting lighter
shade the tail length. The Cambridge Museum of Zoology skin
specimen A6 7.6 has a withered tail, and this is shown as a yellow base
to the column. All imperial measurements have been converted to centimetres
at 2.54cm to 1 inch.
References to the thylacine's body weight (mass) are rarely noted in historical
literature. The few historical measurements that do exist are mainly
19th century in origin, together with the odd Tasmanian newspaper reference
for the weights of animals either captured or killed. Moeller (1968)
noted: "Thylacine body weight varies considerably throughout the records
but anything between 15 to 35 kilograms seems to be the general consensus".
Paddle (2000), in his book "The Last Tasmanian Tiger" notes: "the
average weight for an adult thylacine as being 65 pounds or 29.5 kilograms".
of the body mass in kilograms of seven thylacines.
Source: Dr. Stephen Sleightholme.
The above graph plots
the thylacine body mass measurements in kilograms taken from two historical
sources - e.g., that of Crisp (1855) and Paterson (1805), two 20th century
post-mortem reports of animals that died at the London Zoo, and from three
historical reports in the Tasmanian press [Examiner 1 (22nd November 1887,
p. 2), Examiner 2 (28th May 1887, p. 2) and the Cornwall Chronicle (2nd
September 1868, p. 4)]. The post-mortem reports are those from two
thylacines, one male and one female, which died at London Zoo in 1914.
The body mass for the two specimens was 57½lbs and 29lbs respectively
or in metric equivalent 26.1kg and 13.2kg. Accurate body mass measurements
from a dependable source of this type are very rare indeed.
The mean body weight
represented by this small mixed-sexed sample of seven animals is 23.3kg
(51.3lbs) within a range of 13 to 30.4kg or 28.7lbs to 67lbs. With
most mammals, and in particular marsupials, the maximum body mass is often
two to three times that of the mean for the species.
If we take the mean for this sample group of 22.1kg (48.6lbs), then animals
exceeding 45kg (99lbs) will no doubt have existed
in the general population, although it must be noted that these
would have been exceptional individuals. The Tasmanian newspaper
the Wellington Times & Agricultural & Mining Gazette of the 28th
July 1892 (p. 2) notes the kill of a large "tiger", and cites its weight:
clipping from the Cornwall Chronicle of the 2nd September 1868 (p. 4).
"A large native tiger
was caught here on Wednesday last by Mr. A. Tengdahl; the animal weighed
ll6lbs (52.6kg) and the skin measured 6ft 7in (201cm) long
by 4ft (122cm) across. He was caught in a spring snare, but
broke the springer and got away for a considerable distance, but the broken
portion of the pole caught in some bushes, and by going round and round
he got hopelessly entangled and was shot. The beast is the largest
of the kind I have heard of and has a beautifully marked skin with 17 broad
black stripes across its back".