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reported remains of Acroplous and Trimerorhachis
(two trimerorhachid temnospondyls) and Diplocau-
lus and Brachydectes (two amphibians or 'lepospon-
dyls') in coastal burrows. These would presumably
have been exposed to salt- or brackish water
during the tidal cycle. It could be objected that the
environment represented by that locality is uncer-
tain because Hembree et al. (2005) re-interpreted
the locality as deposits of sporadic ephemeral
ponds in a coastal plain and the burrows as a
response of the tetrapods to seasonal droughts.
However, despite the two different palaeoenviron-
mental conclusions, the deposits of the Speiser
Shale represent a good example of palaeozoic tran-
sitional environments close to or connected to the
sea (Park & Gierlowski-Kordesch 2007) where the
organisms have to adapt to a wide range of salinities
as a consequence of the combination of palaeoenvi-
ronmental (tidal cyclicity, marine incursions) and
climatic factors.
Interestingly, Sequeira (1998) argued that sa-
linity tolerance was the limiting factor explaining
the patchy distribution of saurerpetontids. Accord-
ing to Sequeira (1998, p. 257) the saurerpetontids
'were part of a group of salinity-tolerant tetrapods,
capable of living either in coastal water-bodies
with some saline input, however low, or in period-
ically
populated subaerial areas of the brackish-influenced
coastal plain as indicated by stegocephalian track-
ways in a heterolithic sandstone facies showing
tidal influence (Falcon-Lang et al. 2006, table 2
and fig. 6).
The Puertollano basin preserves a formal coastal,
marine or at least brackish environment, as shown
by the presence of tidal rythmites (a sedimentary
structure which forms only in intertidal and prodel-
taic environments; Mazumder & Arima 2005),
acritarchs, aliphatic hydrocarbons and other geo-
chemical evidence (Laurin & Soler-Gij
´
n 2006,
p. 295). The trackway of Puertollanopus microdac-
tylus, which was produced by a small stegocepha-
lian (pes length of about 20 mm), was left on
intertidal sediments which must have been soaked
with brackish water (Soler-Gij
´
n & Moratalla
2001). The exact identity of the small trackmaker
is not known because the locality in which these
trackways were found did not yield skeletal
remains of a size and shape matching those of the
trackways. The only stegocephalian represented by
skeletal remains is the much larger Iberospondylus
schultzei (Laurin & Soler-Gij ´n 2001, 2006),
whose skull length is about 15 cm. However, the
dimensions and proportions of the tracks and size
and morphology of the impressions of manus and
pes suggest a microsaur or a small reptile. At least
one (perhaps two) species of stegocephalians there-
fore ventured into salt or brackish water in Puertol-
lano in the Stephanian C, which is equivalent to
early
drying
water-bodies
which
might
have
varying salt-content'.
The Late Carboniferous coal fields of Joggins
(Nova Scotia, Canada) and Puertollano (Ciudad
Real, Spain) present stegocephalians (tracks and
skeletal remains) and numerous evidence (geo-
chemical, sedimentological and palaeontological)
of marine influence.
Joggins represents part of the sedimentation in a
large microtidal embayment of an extensive epicon-
tinental sea (analogous in many aspects to the Baltic
Sea) which was connected to the Tethyan Ocean
(Archer et al. 1995; Falcon-Lang 2005; Falcon-
Lang et al. 2006; Falcon-Lang & Miller 2007).
Agglutinated foraminifera (Trochammina, Ammo-
baculites, Ammotium and cf. Textularia) and a
metazoan trace-fossil assemblage (xiphosurian
trackways Kouplichnium and cf. Limulocubichnus
and annelid traces Arenicolites, Gordia, Haplotich-
nus, Plangtichnus, Cochlichnus and Treptichnus)
indicate an 'open water brackish bay' environment
for at least parts of the Joggins Formation (Archer
et al. 1995; Falcon-Lang 2005, fig. 2; Falcon-Lang
et al. 2006, table 1 and fig. 4). The stegocephalian
Baphetes occurred in the brackish bay together
with other osteichthyans (Falcon-Lang et al. 2006,
table 1 and fig. 5), numerous chondrichthyans
(Xenacanthus, Ctenacanthus, Ctenoptychius and
Callopristodus) and acanthodians (Gyracanthus).
In addition, temnospondyls (e.g. Dendrerpeton aca-
dianum)
Gzhelian,
about
304 - 302 Ma
(Davydov
et al. 2004).
Similar conclusions were expressed by Milner
(1987, p. 501), who stated that
This reasoning [which implies that many localities
previously interpreted as freshwater were possibly
brackish] applies to all but one of the other amphibian-
producing localities [Newsham was already discussed
and argued to probably preserve a euryhaline fauna]
from the Coal Measures of England and Scotland,
which are characterized by embolomeres (Panchen
1970), loxommatids (Beaumont 1977) and the occa-
sional keraterpetontid (Milner 1980) and lysorophid
(Boyd 1980). The only exception is the Carre Heys
locality which was offshore deltaic [i.e. with even
more marine influence] and has produced Eugyrinus,
a member of the Trimerorhachoidea, the other group
suggested by Parrish (1978) and Schultze (1985) to
be euryhaline.
Numerous Late Carboniferous - Early Permian
localities with stegocephalians from western and
central Europe (Massif Central in France, Saale
and Saar-Nahe basins and D¨hlen in Germany,
Bohemian basins and Boskovice Furrow in Czech
Republic) (see Table 1) have long been considered
to represent intermontane freshwater basins, palaeo-
geographically far from the sea and located at high
and
lepospondyls
appeared
to
have
