全 文 ：微体古生物学报　 2003年 3月 ; 20( 1): 47- 56
Acta M icr opala eonto log ica Sinica 20( 1): 47- 56; March , 2003
植物分类学在化石珊瑚藻 (珊瑚藻目 ,红藻门 )中的应用
J C BRAGA
Departamen to de Es t ratigrafiay Paleontologí ia, Univ ersidad de Granada, Cam pus Fuen tenueva s /n, 18002 Granada, Spain
提要　最近有人认为将化石藻类的分类归入现生藻类分类单元有利于珊瑚藻作为古环境的标志 ,便于理解该类群
的演化。 然而 ,这样分类可能很难 ,因为并不是所有现生藻类分类特征都能在化石种中保存下来。 Spo ro lithacea科
的钙化部分 (独立或者聚集的孢子囊群 )的出现 ,可以把它们与这个类群的另一个现生科 Co rallina ceae区别开 ,这
个科在生殖窠中产生孢子囊。 节片的有无 ,丝间细胞的联系类型 ,生殖窠中孢子囊释放的数目都是用来划分 Co ral-
linaceae科的亚科的标准 ,在化石样品中也可以用合适的条件进行观察。 在大多数情况下 ,对现生珊瑚藻类属的划
分特征可以在化石藻类中鉴别出来 ,但在几种现生珊瑚藻没有钙化的生殖结构或发育特征。因此 ,它们生殖结构无
法与相应的化石藻类进行对比 ,也不能进行化石藻类的分类。 近年来的趋势认为生殖结构和发育特征是对现生珊
瑚藻进行分类的优先鉴定标准 ,然而 ,某些特征的稳定性在属的划分上仍然存在争论。 在许多情况下 ,现生藻类的
分类标准特征都不能在化石中保存 ,对古生物化石的分类标准的最佳选择是在化石藻类中选择辅助的 ,并且可以
识别的其它鉴定特征 ,或者应用非正式的比现生藻类代表定义更宽的属名。
关键词　　红藻　珊瑚藻　分类
APPLICATION OF BOTANICAL TAXONOMY TO FOSSIL CORALLINE
ALGAE (CORALLINALES, RHODOPHYTA)
J C BRAGA　
Departamento de Estratigraf i′ay Paleontolog i′a. Universida d de Granada , Campus Fuen tenueva s /n , 18002 Granada , Spain
收稿日期　 2002-04-15
改回日期　 2003-02-18
Abstract　 Th e application o f the tax onomy cur rently propo sed fo r living alg ae to fo ssil plants facilita tes th e use of
cor alline alga e as pa laeoenv ironmental indicato rs and favours the unde rstanding o f the evo lutionar y bio log y o f the
g roup. Such application, how ever , might be difficult since no t all th e features used a s diagnostic criteria are pr e-
serv ed in fossil specimens. The occur rence o f calcified compar tments ( iso la ted o r g rouped in so ri) cha racteristics of
the family Spo roli thaceae, r ecognizable in fossil plants, a llow s them to be readily distinguished from Co rallinaceae,
the other living family in the g roup, in which spo rangia develop within conceptacles. Presence /absence of genicula ,
type of the interfilamental cell connections and number of openings in spor ang ia l conceptacles, which a re all cha rac-
ter states used fo r delimiting subfamilies w ithin the family Corallinaceae, can also be obse rv ed with the appropriate
techniques in fossil ex amples. In most cases, diagnostic features fo r sepa rating genera in living cora llines can be
identified in fo ssil plants. It sev era l o ther ca ses, how ever , pr oposed diagno stic cha racter s in ex tant co rallines a re
uncalcified r eproductiv e str uctur es or developmental features tha t ar e not preserv ed and th erefo re canno t be used
fo r g enus identification in ancient mate rial. In recent yea rs ther e ha s been a tendency to pr opose r eproductiv e and
developmental fea tures a s preva lent diagno stic criteria for living co ralline tax onomy. However , the consistency and
systema tic significance o f some of tho se features fo r delimiting gener a is still th e subject o f discussion. In cases in
which diagnostic criteria ar e no t pr eserv ed the best options fo r palaeonto lo gical tax onomy are ancillar y char acters
r ecognizable in fo ssil plants, or the application o f info rma l g eneric names w ith a br oader circumscription than in
liv ing r epr esenta tiv es.
Key words　　 red algae　 corallines　 tax onomy
INTRODUCTION
Using a tax onomy fo r fossil co ralline algae a s
simi lar as possible to the taxonomy applied to pre-
sent-day co ral lines is very important fo r recon-
st ructing the evolutiona ry histo ry of the group.
This is also relev ant to the po tential utili za tion of
coralline alg ae as palaeoenvi ronmental indicators,
w hich are most ly based upon comparison of fossi l
alg al assemblages wi th the envi ronmental and geo-
g raphical dist ribution of modern algal a ssociations.
The application of the tax onomy for living algae to
fossil plants, how ever, might be di fficult since not
all the characters that can be po tentially used as di-
agnostic cri teria a re preserv ed in fossi l specimens.
The diagno stic cri teria used fo r sepa ra ting
taxa a t di fferent tax onomic lev els have changed
through the histo ry of biological and palaeobiolog-
ical research in all g roups of o rganisms and the
coralline red a lg ae have not been an exception. In
addition, throughout the history of the research on
corallines, no general ag reement on the classifica-
tion of living and fossil alg ae has been reached and
new ly proposed ci rcumscriptions of tax a have been
continuously appea ring.
The monog raphy by Woelkerling ( 1988) is the
most complete and comprehensiv e recent study of
g eneric and suprageneric taxonomy o f the Coralli-
nales. It proposed a classification scheme fo r non-
geniculate corallines based upon a series of diag-
nostic characters, many of w hich are recognizable
in fossi l ex amples. Key features fo r delimi ting sub-
fami lies, and most of the diagnostic cha racters
used by Woelkerling ( 1988) at generic lev el , can be
observ ed in fossil plants wi th appropriate optical
microscope and SEM techniques ( Braga et al . ,
1993) . In recent y ears, however, the circumscrip-
tion of some living genera previously delimited by
vegetativ e features recognizable in fo ssil ex amples
ha s been substantially modified. Cha racters w ith
no o r very-low preserv ation po tential , such as fea-
tures of spermatangia, have been proposed as diag-
no stic ( Penro se, 1992; Camberlain& Kea ts, 1994;
Woelkerling , 1996a-c) , making the identi fica tion of
the co rresponding ci rcumpscriptions o f genera in
fo ssi l co rallines dif ficul t o r impossible. In addi-
tion, the mo rphological scheme of subfamily classi-
fica tion, propo sed by Johansen( 1981) and adopted
by Woelkerling ( 1988 ) wi th modi fica tions, has
been challenged by gene sequence analyses( Bailey,
1999)
In this paper, I analy se the applicabi li ty to
fo ssi l non-geniculate corallines of the diagnostic
cri teria used at present by phycologists fo r identi-
fying families, subfami lies and genera in living rep-
resentativ e. As has been happening in the past
years, sev eral o r ev en many of these cri teria and
the subsequent ci rcumscriptions of g enera and
higher taxa wi ll probably change in the nea r
future. Taking this into account , this paper only
repo rts the state of the ar t at the beginning of
2002.
SUBFAMILIES
Woelkerling ( 1988) propo sed the subfami lial
subdiv ision of the Co rallinaceae show n in Table 1.
Key features in this classif ica tion scheme are the
presence /absence of genicula ( uncalci fied sege-
ments of the thallus) , the number of po res o f the
sporeproducing conceptacles ( Figs. 1 and 2) , the
type of interfi lamental cell connections ( Fig. 3) ,
and the presence /absence of spo rangial plug s( Fig.
2) . V erhei j ( 1993) sepa ra ted Sporol ithon f rom the
subfamily Melobesioideae, establishing the new
fami ly Spo roli thaceae, characterised by cruciately
arranged spo res in contrast to the zonately a r-
ranged spo res in the fami ly Corallinaceae ( Fig s. 1
and 2 ) . Spo res in the spo roli thaceans are produced
48 微　体　古　生　物　学　报 20卷　
Table 1　 Key characters of subfamilies of the Corallinaceae according to Woelkerling ( 1998)
g enicula number of po res
sporangial conceptacles
predominan t interf ilamental
cel l connections
sporangial
plugs
Amphi roideae pres en t unipo rate second ry pit s absent
Corallinoid eae pres en t unipo rate cell fusions absent
Metagonioli th oid eae pres en t unipo rate cell fusions absent
Cho reonematoideae absent unipo rate absent pres en t
Lithoph yl loideaea absent unipo rate s econdary pi t s absent
Mas tophoroideae absent unipo rate cell fusions absent
Melobesioideae absent m ultiporate cell fusions pres en t
Fig. 1　Vertical section of a decalcified thallus ma rgin　 ( a ) and a matur e ( bi) spo rangial conceptacle of L ithophyllum pustula -
tum ( = Titanoderma pustulatum ) ( b) . Taken from Cham ber lain and Irv ine( 1994) . No te the dimerous o rganisa tion: a system
o f filaments ( system 1) runs par allel to th e ventral ( low er) sur face at right angles to the filaments arising from them ( system
2) . The spor ang ia l conceptacle is unipo ra te and includes a columella: a g r oup of sterile filaments a t the cent re o f th e concepta-
cle floo r
w ithin calcified compa rtments that may be g rouped
in so ri. Subsequently , the subfamily Aus-
troli thoideae Ha rvey & Woelkerling 1995, wa s es-
tablished to include corallines wi th no interfi lamen-
tal cell fusions but having multipo ra te concepta-
cles.
Gene sequence analyses of small-subuni t ribo-
somal RN A( 18S rRN A) , how ever, suggest close
af fini ty of the genicula te Amphiroideae and the
non-geniculate Li thophy lloideae. Ult rast ructural
studies( Broadwa ter et al . , 2000) also suppo-rt the
inclusion o f both g roups in a sing le subfamily
Li thophylloideae Setchell emend. Bailey, 1999
characterised by uniporate sporangial conceptacles
and secondary pi t connections ( Bailey, 1999 ) .
These characters are preservable in fo ssil
specimens . The rest of the subfamilies can also
be distinguished on the basis of cha racters recog-
49　 1期 J C BRAGA等: 植物分类学在化石珊瑚藻 (珊瑚藻目 ,红藻门 )中的应用
Fig. 2　 Ver tical section o f a decalcified tha llus and ( tetr a)
spor angia l conceptacle o f Phymatolithon lenormandii
Taken from Chambe rlain and Irvine ( 1994) . The thallus is
monomerous, i. e. consists of a sing le system of repeatedly
branched filaments, and its cor e is plumose. The concepta-
cle is multipor ate containing tetr aspo rangia with apical
plug s. Some cells o f adjacent filaments a re fused
nisable in fossil specimens( occur rence of g enicula,
number of sporangial conceptacle pores and inter-
fi lamental cel l connections) which are consistent
w ith gene ana lyses. The Mastopho roideae, how ev-
er, may be po lyphy letic acco rding to ult rast ruc-
tural features show n by i ts members ( Broadwa ter
et al . , 2000) .
　　 The modi fica tions introduced into W oelke-
rling s ( 1988) classification scheme since its publi-
cation are show n in the suprageneric tax onomy of
living co rallines in Table 2. Three subfamilies of
Co ral linaceae have never been repor ted as fo ssil s
and w ill not be treated in the following section.
Aust ro li thoideae and Choreonema toideae include
small, largely unconsolida ted, endophy tic o r
epig enous plants w ith very low preserv ation poten-
tial, w hi le Metagoniolithon , the only g enus as-
signed to M etagoniolithoideae, is biog eog raphical ly
rest ricted to a region ( southern and southw ester n
Aust ralia ) ( Womersley & Johansen, 1996) f rom
which there are no published repor ts on fo ssil
Corallina les.
　　 The clea r morpho logical di fferences betw een
the calci fied compa rtments ( isolated or g rouped in
so ri ) characteristics of Sporo li thaceae and the spo-
rangia l conceptacles of Co rallinaceae, bo th recog-
nisable in fossil plants allow the tw o families to be
readi ly distinguished in ancient co rallines. Occur-
rence of g enicula, interfilamental cell connections
and number o f opening s in spo rangial conceptacles
can also be observed w ith the appropriate tech-
niques in fossil ex amples ( Braga et al . , 1993) .
GENERA
Subfamily Lithophylloideae
The small epiphy tic plants of the genus Ezo
have very low preserv ation potentia l and a re un-
known as fossi ls. The isobila teral o rganisation of
Tenarea is readi ly recognisable in fo ssil plants a l-
though the genus seems to be geog raphically re-
stricted to the eastern Mediterranean. The only
problema tic circumscription wi thin the subfami ly is
fo r the species belonging to the Li thophyllum-Ti-
tanoderma complex but such dif ficulties in generic
assignment affect living plants a s much as fossi ls.
Titanoderma was fo rmerly distinguished from
Lithophyl lum by having primig enous fi laments
composed of palisade cells in the dimerous po rtions
of thalli ( Fig. 1) ( Woelkerling , 1988) . subsequent-
ly, Campbell and Woelkerling ( 1990) wo rking w ith
southern Aust ralian plants concluded tha t palisade
and non-palisade cel ls co exist in sing le specimens
and in specimens of a sing le popula tion and there-
fo re canno t be used as dignostic cri teria. This
opinion is fo llow ed by Woelkerling ( 1996a ) , but
Chamberlain ( 1991) and Chamberlain and Irvine
( 1994 ) consider that Titanoderma can be dis-
tingished by the presence of pa lisade cells and epi-
thallial cell s only at the margins of dimerous po r-
tions o f thalli ( Fig. 1a ) . Gene sequence analy sis
ca rried out in the type species of both genera suggests
a certain deg ree o f dif ferentiation of Titanoderma
50 微　体　古　生　物　学　报 20卷　
Table 2　 Key characters of subfamilies of the Corallinaceae and Sporolithaceae, including the modif ications of Verheij
( 1993) , Harvey and Woelkerling( 1995) and Bailey( 1999) to the classif ication of Woelkerling( 1988)
CO RALLINACEAE g enicula number of po res
sporangial
concep tacles
p redominant
interf ilamental cell
conn ections
sporangial
plugs
fossi ls
Corallinoid eae pres en t unipo rate cell fusions absent comm on
Metagonioli th oid eae pres en t unipo rate cell fusions absent u nknow n
Aus t roli th oideae absent m ultiporate absent pres en t u nknow n
Cho reonematoideae absent unipo rate absent pres en t u nknow n
Lithoph yl loideaea absent /pres en t unipo rate s econdary pit s absent comm on
Mas tophoroideae absent unipo rate cell fusions absent comm on
Melobesioideae absent m ultiporate cell fusions pres en t comm on
SPORO LTI HACEAE spores cruciately arrang ed, calci fied compartmen ts , s ori comm on
Fig . 3　 The tw o types o f inter filamental cell connections in co ra lline r ed alga e
a) secondar y pit connections. b) cell fusions
and Litho-phyllum ( Bai ley , 1999) but ex cept for a
few typical species f rom non-tropical seas of the
No rthern Hemisphere the morphological sepa ra tion
o f the tw o genera remains dif ficul t and uncertain.
SubfamilyMastophoroideae
Among the living forms o f this subfami ly, the
small epiphy tic genus Lesueuria and arborescent
and flexible plants o f Metamastophore are unknow n
as fossils. Apart f rom these, the key to g enera
wi thin the subfamily acco rding to Woelkerling
( 1996b) is show n in Table 3. The ventral layer of
palisade cells separating Mastophora -Lithoporella
f rom other g enera can be recognised in fo ssil
plants. Within this g roup, the only fea ture sepa-
rating Mastophor f rom Lithoporella preserv able in
fo ssi ls i s the remains o f a central co lumel la. Such
remains are known from conceptacles in Lithophyl-
lum plants ( Braga & Aguirre, 1995) but have
51　 1期 J C BRAGA等: 植物分类学在化石珊瑚藻 (珊瑚藻目 ,红藻门 )中的应用
Table 3　Key features of the living Mastophoroideae according to Woelkerling ( 1996b)
Genera with very low preservation potential are not included
1. Th al lus w ith a conspicuous vent ral layer of pali sade-cel l fil am ents 2
1. Th al lus lacking a conspicuous vent ral layer of pali sade-cel l filaments 3
2. Sporangial conceptacles w ith a cent ral colum ella, roofs formed only by
fi lamen ts peripheral to th e spo rangial initi al s, sporangia confined to the
periph ery of the conceptacle ch am ber f loor Mastop hora
2. Sporangial conceptacles lacking a cent ral colum ella, roofs formed by
fi lamen ts peripheral and interspers ed amongs t th e sporangial init ials, spo rangia
scat tered across the conceptacle chamber floor Lithoporel la
3. Sporangial conceptacle po re canals lined b y cell s orien tated more or les s
perpendicularly to the roof surface. No cel ls prot rude lateral ly into the po re
canal. Hydroli thon
3. Sporangial conceptacle po re canals lined b y cell s orien tated more or les s paral lel
to the roof surface. Som e cel ls prot rude lateral ly into the po re canal 4
4. Sporangial conceptacle roofs formed by f ilaments su rrou nding and
interspers ed amongs t sporangial initi al s Pneophyllum
4. Sporangial conceptacle roofs formed by f ilaments periph eral to the sporangial ini tials
5
5. Spermatangia on ly form ed on the f loo rs of male concep tacle chambers;
gonimoblas t fi lamen ts arising f rom periph eral surfaces of fusion cell s Spongi tes
5. Spermatangia form ed both on the f loors and roofs and male concep tacle
chambers; gonimoblas t f ilaments arising f rom dorsal surfaces of fusion cell s Neogoniolothon
never been repo rted in fossi l mastophoroids. In
fact, there are no confi rmed reco rds of ancient
Mastophora.
　　 The orientation o f cells lining the pore canals
can be observ ed in conceptacles of fossil plants,
thus allowing the identification of Hydrol ithon. In
contrast , th e characters separating genera w ithin
the Pneophyllum-Spongites-Neogonioli thon complex
a re related to conceptacle roof development and
dist ribution o f repo rductiv e st ructures inside con-
ceptacles w hich have very low preserv ation poten-
tial. These genera, therefo re, canno t be distin-
guished in fossil algal assemblages according to the
tax onomic cri teria applied by phycologists to liv ing
representativ es. A possible taxonomic procedure to
cope wi th this problem is to refer the fossi l plants
o r the identified species to a“ genus complex” with
info rmal names to convey the informa tion that the
alg a o r alga e in question belong to this g roup even
if i t i s no t possible to giv e them a precise g eneric
ci rcumscription. Al terna tiv ely, the taxonomic cri-
teria of Braga et al . ( 1993) deriv ed f rom Woelker-
ling ( 1988) can be applied. This la tter procedure
implies acceptance that Pneophyllum canno t be
recognised in fossi l assemblages and that plants po-
tentially pertaining to this g enus are included in ei-
ther Spongites o r Neogoniol ithon. Addi tionally,
fo ssi l N eogoni lithon i s characterised by the occur-
rence, at least in some po rtions o f the thallus, of a
v entral coaxial core w hich is absent in Spongites.
The occurrence o f a coaxial core is conspicuous in
the type species of Neogoniolithon [ N . fosliei
( Heydrich ) Setchell et Mason ] and w as until re-
cently ( Penrose, 1992) considered the main diag-
no stic character of the genus w ithin the subfami ly.
The application of this tax onomy allow s use of a
binomial although w e should be awa re that the ci r-
cumscription of the generic names can dif fer slight-
ly fo r living and fossi l corallines.
52 微　体　古　生　物　学　报 20卷　
Subfamily　Melobesioideae
The small epig enous tha lli of Kvaleya have
never been recorded as fossi ls. The flexible, ar-
borescent plants of the monospecific g enus
Mastophorosis , rest ricted to southern Aust ralia,
a re also unknown as fossi ls and I do no t refer to
them in the following section. Table 4 combines
key fea tures proposed by Woelkerling ( 1996c) fo r
melobesioid genera w ith data of Camberlain and
Keats ( 1994) and Chamberlain et al . ( 1995) on
Clathromorphum.
　　 Dimerous ( Fig. 1) and monomerous ( Fig. 2)
thallus const ructions can easi ly be recognised in
fossil plants. Melobesia and Ex ilicrusta Chamber-
lain 1992 are the only genera wi th dimerous org ani-
za tion o f cell fi laments. Ex ilicrusta is unknown a s
fossil and its repor ts a re so far restricted to the
Briti sh Isles. There are no confirmed reco rds of
fossil Melobesia al though this name has been w ide-
ly used to refer to “ co ralline algae” in g eneral in
the geological li terature.
　　Within melobesioids wi th monomerous o rgani-
zation, the character separating Lithothamnion
f rom the other genera, the occurrence of f lat epi-
thallial cells wi th f lared distal walls, can be ob-
serv ed in some instances in fo ssil specimens but ex-
cellent, unusuall preservation is required. Persis-
tent ly f lat tened epithal lial cells can easi ly be recog-
nised in fossil plants and this can be used as an an-
cillary character state fo r identi fying fo ssil
Lithothamnion. Even i f f lat tened epi thaliall cells
may occur in plants belonging to o ther genera,
they a re usually sparse among st rounded ones in
the same thallus. The sho rt subepitha llial cells
characteristic of Phymatoli thon can be identi fied in
fo ssi ls ( Rasser& Piller, 1999) , al lowing separation
of the genus f rom the Synarthrophython-Mesophyl-
lum -Clathromorphum complex ( Fig. 4) . M odern di-
agnostic cri teria for g eneric ci rcumscription wi thin
this complex are no t recognisable in fossi l plants.
Synarthrophyton i s separated f rom Mesophyl lum
( and Clathromorphum ) by having branched
Table 4　Key features of the living Melobesioideae according to Woelkerling ( 1996c)
Genera with very low preservation potential are not included
1. Th al lus dim erous E xil icrusta, Melobesia
1. Th al lus monom erous 2
2. Dis tal wall s of terminal epithallial cells f lat tened and f lared Lithothamnion
2. Dis tal wall s of terminal epital lial cel ls round ed or f lat tened but
not f lared 3
3. Sub epithallial ini tials as shor t as o r sh orter th an the cel ls
immediatelly su btending them; sporangial conceptacles arising
adventi ti ously f rom groups of veg etative cel ls wi thin th e th allus Phyma tol ithon
3. Sub epithallial ini tials as long as or longer th an the cell s
immediatelly su btending them; sporangial conceptacles arising
adventi ti ously f rom groups of subepi thalli al ini tials 4
4. M ale conceptacles wi th mos t ly branched spermatangial
fi lamen ts3
Synar throphyton
4. M ale conceptacles wi th only u nbranched spermatangial fil am ents 5
5. Male conceptacle roof develops f rom filam en ts surrounding
spermatangial init ials Mesophyllum
5. Male conceptacle develops in cells cut of f f rom, and subtending,
sub epithallial cell s Clathromorphum
53　 1期 J C BRAGA等: 植物分类学在化石珊瑚藻 (珊瑚藻目 ,红藻门 )中的应用
Fig. 4　 Schematic representation of the two types o f subepithallia l initials
used as diagno stic g ene ric chara cter sta tes within th e subfamily
Melobesioideae
( a) Subepithallial initials a s sho rt as o r sho rter than, the cells immedia telly subtending them
( b) Subepitha llial initials as long a s o r longer than, the cells immediatelly subtending th em
sperma tangial fi laments. This character state is
conspicuous in the type species o f Synarthrophyton
( S. patena) but is much less clear in o ther species
a tt ributed to the genus that po ssess only w eakly
branched spermetangial fi laments. There is, there-
fore, a g radation between the simple sperma tangial
systems of the type species o f Mesophyl lum (M.
l ichenoides ) and the complex ones in S. patena and
the taxonomic signi ficance of this cha racter needs
to be evaluated ( Keats & Chamberlain, 1997) .
　　 As in the case of the complex of mastopho roid
genera distinguished by fea tures no t preserv able in
fossils , a possible taxonomic procedure is to assign
fossil plants o r identified ancient species to a
“ genus complex” using informal names. Alterna-
tiv ely, fo llow ing Braga et al . ( 1993) , Mesophyllum
can be identified by the occurrence o f coaxial ar-
rangement at least in some po rtions o f the ventral
core. Although the coaxial a rrangement is an an-
ci llary character, all know n living species a t tribut-
ed to Mesophyl lum show such an ar rangement in
some pa rt o f the thallus. Clathromorphum , w hich
has not been repo rted as a fossil, would be charac-
terised by the presence of sev eral epithallial cells in
each fi lament. Synarthrophyton , also unknown as
fo ssi l, w ould be delimi ted by the absence o f the
features cha racteristic of the o ther tw o genera of
the complex , making i ts identification very uncer-
tain. In addi tion to the genera included in Table 4,
the sta tus of the genus Leptophytum Adey is con-
trov ersial. Du wel and Wegeberg ( 1996) consider i t
a younger hetero typic synonym of Phymatol ithon,
w hilst Adey et al . ( 2001) recognised the genus and
sepa ra ted i t f rom Phymatolithon on the basis of
sev eral cha racters. In the case tha t such characters
actua lly have tax onomic relev ance at g eneric level,
Leptophytum cannot be sepa ra ted f rom Phyma-
tolithon in fo ssil assemblages since these characters
are reproductiv e, developmental and even cellstain-
ing fea tures.
CONCLUDING REMARKS
Applying a tax onomy as clo se as possible to
the one emplo yed fo r present-day co rallines to fos-
sil coralline algae favours th e utili za tion of coralline
algae as palaeoenvironmental and palaeogeo-
graphical indicators by direct comparison o f living
54 微　体　古　生　物　学　报 20卷　
and fo ssil representativ es. Following a unified
classi fica tion also facilitates the interpretation of
the evolutiona ry histo ry o f the g roup.
Diagno stic features fo r delimi ting families and
subfami lies and many diagno stic characters used a t
the generic level w ithin Corallinales can be ob-
serv ed in fo ssil plants w ith appropriate optical mi-
croscope and SEM techniques. In some cases,
how ever, the proposed diagno stic cha racters fo r
separating genera in liv ing corallines cor respond to
uncalcified reproductiv e structures o r to develop-
menta l features wi th very low preserv ation poten-
tial in fossi l co ralline algae. Such characters cannot
be recognised in fo ssil plants and therefo re cannot
be used for g enus identification in ancient ma terial.
The consistency and systematic significance of
some of those features is still the subject of discus-
sion and there is no cur rent general ag reement
among phyco logists concerning the generic tax ono-
my applicable to liv ing corallines.
Using ancillary characters preservable in fossi l
plants, o r giving informal g eneric names applied to
fossils a broader ci rcumscription than that given to
living co ra llines, or combinations of both proce-
dures, seem to be the best options fo r the palaeon-
tological tax onomy of coralline alg ae. In these cas-
es, i t is impo rtant to refer to the ci rcumscription
implied by any particular applica tion o f a name, in
case it di ffers from that general ly accepted in the
tax onomy of living co rallines.
REFERENCES
ADEY W H, ATHANAS IADIS A, LEBEDNIK P A, 2001. Re-in-
s tatemen t of Leptophytum and it s type Leptophytum laeve: tax-
on omy and biogeog raph y of th e genera Lep tophytum and Phy-
matoli thon ( Corallinales, Rh odophyta) . Eur. J. Ph ycol. , 36:
191— 203
BAILEY J C, 1999. Ph ylogenet ic positi ons of Lithophyllum incrus-
tans and Titanoderm a pustu latum ( Corallinaceae, Rh od oph yta)
bas ed on 18S rRN A gene sequence analyses, wi th revi sed clas-
si fi cation of th e Li th ophylloideae. Phycologia, 38: 208— 216
BRAGA J C, AGU IRRE J, 1995. Taxonomy of fossil coralline algal
species: Neogene Lithoph yl loideae( Rhodoph yta, Corallinaceae)
f rom sou thern Spain. Review of Palaeobotan y and Palynology,
86: 265— 285
BRAGA J C, BOSEN CE D W J, ST EN ECK R S, 1993. New
anatomical characters in fos sil co ralline algae and th ei r taxo-
nomic im plications. Palaeontology, 36: 535— 547
BROADWAT ER S, SCO TT J, M ILLIE D F, KURGEN S P, 2000.
A re-evaluation of co ralline red algal taxonom y using ul tra-
s t ructural information. 54. Annual Meething of the Phycologi-
cal Society of America, San Diego, CA( U SA) , 15— 19 Ju ly,
2000, Journal of Phycology 2000. 36, 37
CAMPBELL S J, WOEL KERLING WM J, 1990. Are Titanod erma
and Lithophyllum ( Corallinaceae, Rhodophy ta) dis tinct genera?
Phycologia, 29: 114— 125
CHAMBERLAIN Y M, 1991. Historical and tax onomic studies in
the genus Titanoderma ( Rhodoph yta, Corallinales ) in the
Brit ish Is les. Bul letin Bri ti sh Museum ( Natural His tory ) ,
Botan y Series, 21: 1— 80
CHAMBERLAIN Y M, 1992. Observat ions in tw o melobesioid crus-
tose coralline red alagal species f rom th e Briti sh Isles: Exili-
crusta parva, a n ew genus and sp ecies, and Li thothamnion son-
deri Hauck. Bri tish Ph ycological Jou rnal , 27: 185-201
CHAMBERLAIN Y M , IRV IN E L M, 1994. Li th ophylloideae. In:
L M IRV IN E and Y M CHAM BERLAIN ( eds. ) . Seaw eeds of
the Briti sh Iseles. Vol. 1, Part 2B, Corallinales and Hi ldebran-
diales. HMSO, London, pp. 58— 112
CHAMBERLAIN Y M , KEAT S D W, 1994. Th ree melobesioid
crus tose coral line red algae f rom Sou th Africa: Lep toph ytum ac-
erva tum ( FOSLIE) comb. nov. , L . fovea tum sp. nov. and L .
f erox ( FOSLIE) comb. nov. Phycologia, 33: 111— 133
CHAMBERLAIN Y M , NO RRIS R E, KEATS D W, M AN-
EV ELDT G, 1995. Cla thromorphum tubiforme sp. nov.
( Rhodophy ta, Coral linaceae) in South Africa wi th commen ts on
generic characters. Botanica Marina, 38: 443— 453
DU
　··
WEL L, WEGEBERG S, 1996. Th e typif icat ion and status of
Leptophytum ( Corallinaceae, Rh odophyta ) . Ph ycologia, 35:
470— 483
HARVEY A, WOELKERLING W J, 1995. An accoun t of Aus-
t rol ithon intum escens g en. et sp. nov. and Boreoli thon van-heur-
cki i ( Heydrich ) gen. et comb. nov. ( Aus troli th oid eae subfam.
nov. , Coral linaceae, Rhodoph yta) . Ph ycologia, 34: 362— 382
JOHANSEN HW, 1981. Coralline Algae, A Firs t Synth esi s. CRC
Press , Boca Raton, 239 pp
KEAT S D W, CHAMBERLAIN Y M, 1997. Th e non-geniculate
coralline algae Syna rtrophyton eckloniae ( Foslie) com b. nov.
and S . magel lan icum ( Foslie) comb. nov. ( Rh odophyta ) in
South Africa including comparis on w ith relevant types. Eur. J.
Phycol. , 32: 55— 79
PEN ROSE D, 1992. N eogoniol ithon fosl iei ( Coral linaceae,
Rhodophyta) , the type species of Neogonioli thon , in southern
Aus t ralia. Ph ycologia, 31: 338— 350
RASSER M W, PILLER W E, 1990. Application of neon tological
tax onomic concepts to Late Eocene co ralline algae( Rhodoph yta)
55　 1期 J C BRAGA等: 植物分类学在化石珊瑚藻 (珊瑚藻目 ,红藻门 )中的应用
of the Aust rian Molasse Zone. Journal of M icrrpaleontoogy,
18: 67— 80
VERHEIJ E, 1993. Th e genus Sporol ithon ( Sporoli thaceae fam.
nov. , Corallinales, Rh odoph yta ) f rom th e Spormode Archip-
ielago, Ind onesia. Ph ycologia, 32: 184— 196
WO ELKERLING W J, 1988. Th e Coralline Red Algae, An Analy-
sis of Genera and Subfami lies of Nongeniculate Corallinaceae.
Ox fo rd Universi ty Press , Oxford and Bri tis h Museum ( Natu ral
History) , London, 268pp
WO ELKERLING W J, 1996a. Sub family Li th ophylloid eae. In:
WOM ERSLEY H B S ( ed. ) . The Marine Benthic Flora of
Southern Aus t ralia. Rhodophyta Par tⅢ B. Aust ralian Biological
Resources Stud y, Canberra, pp. 214— 237
WOELKERLING W J, 1996b. Subfamily Mas topho roid eae. In:
WOMERSL EY H B S ( ed. ) . Th e Marin e Benthic Flo ra of
South ern Aust ralia. Rh od oph yta PartⅢB. Aus t ralian Biological
Resources Study, Can berra, pp. 237— 283
WOELKERLING W J, 1996c. Subfami ly M elobesioideae. In:
WOMERSL EY H B S ( ed. ) . Th e Marin e Benthic Flo ra of
South ern Aus t ralia. Rh odoph yta PartⅢ B. Aus t ralian Bilogical
Resources Study, Can berra, pp. 164— 210
WOM ERSLEY W J, JO HAN SEN H W, 1996. Su bfamily Metago-
nioli th oid eae. In: WOMERSL EY H B S ( ed. ) . Th e Marine
Benthic Flora of Sou th ern Aust ralia. Rh odoph yta Part Ⅲ B.
Aus t ralian Biological Resources Study, Canberra, pp. 317— 323
　《微体古生物学报》勘误:
　第 19卷 ,第 3期 ,第 215页:作者“武井雅彦”应改为“长桥彻”　
56 微　体　古　生　物　学　报 20卷