I58
B. STONEHOUSE
Fossil penguins have been recorded from Patagonia, Seymour Island
(Antarctic Peninsula), New Zealand and Australia. Accounts of fossil
material by Huxley (1859), Ameghino (1905), Wiman (1905) and Finlayson (1938) were discussed critically by Simpson (1946), who referred all
specimens then known to the Miocene. He reduced the tally of genera
from over 20 to seven, and of species from over 30 to about a dozen.
Marples (1952) reassessed some of the classical New Zealand specimens
and described new material from several South Island localities. On the
evidence of matrix Foraminifera he showed that all the New Zealand
fossils were from Eocene or Oligocene formations, and described a
number of anatomical points on which they could be judged more
primitive than Patagonian forms. In a later paper (1953) he confirmed
that the Seymour Island specimens were mid-Tertiary rather than early
Tertiary forms. Thus fossil material ranging in age from early Eocene
to early Miocene, and representing a t least two stages of evolution, is
available for comparison with modern forms. All lies within the presentday geographical range of penguins, and probably represents species of
temperate or warm climates. The size of fossil penguins is discussed
later (p. 177).
B. SEA TEMPERATURES AND TERRESTRIAL CLIMATES
Ranges and means of sea and air temperatures, derived from isotherm
charts for February, May, August and November (Schott, 1926, 1935)
are graphed in Fig. 7. The represented sea temperature range is derived
from the highest and lowest isotherm values (usually for February and
August) for each station, and the mean is that of the four charted
months. These data compare well with published values from other
sources (e.g. Paulian, 1953, p. 139 for Kerguelen; Wace, 1960, p.
477 for Gough Island; Rand, 1955, p. 57 for Marion Island); they do
not take into account temperature fluctuations in sheltered coastal
waters, which are in any case unlikely to affect many species of penguins
seriously.
Air temperatures are similarly derived from Schott’s quarterly isotherms, which are means for their respective months and do not indicate
the overall temperature range for the station. Most penguins live close
to the sea, many on small islands where air temperatures are stabilized
by the surface temperature of the surrounding water. The air temperature
ranges shown may therefore represent conditions in a penguin microhabitat at least as faithfully as published climatic ranges. For comparison, and for details of polar and sub-polar climates where the incidence
of extreme temperatures may be important, Fig. 8 shows seasonal
temperature frequency curves for a range of climatic stations in the
temperate, sub-antarctic and Antarctic zones.
B. STONEHOUSE
Fossil penguins have been recorded from Patagonia, Seymour Island
(Antarctic Peninsula), New Zealand and Australia. Accounts of fossil
material by Huxley (1859), Ameghino (1905), Wiman (1905) and Finlayson (1938) were discussed critically by Simpson (1946), who referred all
specimens then known to the Miocene. He reduced the tally of genera
from over 20 to seven, and of species from over 30 to about a dozen.
Marples (1952) reassessed some of the classical New Zealand specimens
and described new material from several South Island localities. On the
evidence of matrix Foraminifera he showed that all the New Zealand
fossils were from Eocene or Oligocene formations, and described a
number of anatomical points on which they could be judged more
primitive than Patagonian forms. In a later paper (1953) he confirmed
that the Seymour Island specimens were mid-Tertiary rather than early
Tertiary forms. Thus fossil material ranging in age from early Eocene
to early Miocene, and representing a t least two stages of evolution, is
available for comparison with modern forms. All lies within the presentday geographical range of penguins, and probably represents species of
temperate or warm climates. The size of fossil penguins is discussed
later (p. 177).
B. SEA TEMPERATURES AND TERRESTRIAL CLIMATES
Ranges and means of sea and air temperatures, derived from isotherm
charts for February, May, August and November (Schott, 1926, 1935)
are graphed in Fig. 7. The represented sea temperature range is derived
from the highest and lowest isotherm values (usually for February and
August) for each station, and the mean is that of the four charted
months. These data compare well with published values from other
sources (e.g. Paulian, 1953, p. 139 for Kerguelen; Wace, 1960, p.
477 for Gough Island; Rand, 1955, p. 57 for Marion Island); they do
not take into account temperature fluctuations in sheltered coastal
waters, which are in any case unlikely to affect many species of penguins
seriously.
Air temperatures are similarly derived from Schott’s quarterly isotherms, which are means for their respective months and do not indicate
the overall temperature range for the station. Most penguins live close
to the sea, many on small islands where air temperatures are stabilized
by the surface temperature of the surrounding water. The air temperature
ranges shown may therefore represent conditions in a penguin microhabitat at least as faithfully as published climatic ranges. For comparison, and for details of polar and sub-polar climates where the incidence
of extreme temperatures may be important, Fig. 8 shows seasonal
temperature frequency curves for a range of climatic stations in the
temperate, sub-antarctic and Antarctic zones.