The snakes (Reptilia, Serpentes) of the Miocene of Portugal

(

Ciênci as da Terra (UNL)

1

Lisboa

1

pp .359 -364

2

pl.

2000

)

The snakes (Reptilia, Serpentes) of the Miocene of Portugal

Zbigniew Szyndlar

Polish Academy of sciences. lns titute ofSyslematics and Evolution ofAnimaIs. Slawkowska 17, 3 1-016 Krakow, Poland.

ABSTRACT

Key-wo rds: Snakes [Reptilia): Boids; Co lubri ds; Oriental vipcrs; Mioccne; Portugal.

The ophidien fauna coming from the Miocène of ArnOT (MN 5), Quinta das Pedreiras and Qu inta do Pombeiro (bo th MN4 ) (Portugal) consists of the follo wing taxa: cf.Bavarioboasp. (Boidae); cf.Colubersp. (Co luh ridae ); two u nidcntified Co lubridae ;

Piperasp. (" Oriental vipers" complex) (Vipcri dae). The assemblage is characteristic for the lowe r/middlc Miocen e trans ition and il

rese mbles snake fauna s known from et her Europea n localitics of sim ilar age.

RESUMO

Pal avra s chave: Se rpentes [Reptilia; Boideos; Colubridcos ; viboras orientais; Miocénico; Portugal.

As faunas de ofideos do Miocénico de Arnor (MN 5), Qu inta das Pedreiras e Quinta do Pombeiro (amb as MN4), em Portugal, consistcm nos seguintes taxa: cf.Bavariobasp. (Boidae]; cf.Cotubersp. (Colubridac); do is colu brideos indctcrminados;viperasp. (complexo de "viboras orien tais") (Vipcridae). A associaçâo é caracteristica da transiçâo do Miocénico infe rior para 0 Mioc énico m édie; assemclha-sc ès faunas de ofldeos curopcias de idade similar.

I NTROD UCTIO N

The first presence of snakes in Portugal has bee n re -ported from the Cre taceo us period. Th ese ophidie ns, rep-rescnted by poo rly preserv ed foss ils, were th e marine

Simolioph is(Sa uvage, 189 6) and an unident ified

terres-trial booid (R age, 198 1). Thus far, the only Paleogen e ter-restrial snakes rcported from Portugal are a late Paleocene or Lowermost Eoc ene Boid from Silveirinha (Antu nes, 198 1; Antun es & Russell, 198 1). Th e cld es t subseq uent fossil reco rd of Port ugue se ophidians cornes fro m the Miocene. T he pre sent pap er discu sses the taxonomi e po-sition of the latter sna kes.

The snake remains from the Portu guese

Mioc ène

avail-able for study have been found in thre e loc alities: Am or, Quint e das Pcdreiras, an d Q uinta do Pombeiro (b iozone MN 5; Antunes&Mein, 1981; M.T.Antunes, pers. comm.; Ant unes , this volume) . T he mate rial is consisted of sev-eral trunk.verteb rae, us ually in bad state of preserv ation ; no cranial ele ments hav e bee n foun d.

Th e entire material fro m the Portuguese M io c ène, exc ept for two vert eb rae , was previously desc ribed by Antunes& Rage (19 74) . Ant unes & Rage identified the

ophidia n fossils to th e fa m il y leve l o n ly: Bo idae , Colubrida e, and Viper idae. No doubt, more precise ide n-tificat ion of the remains was impossible at those limes, mainly due to the fact that low er/middle M iocène snake fauna s of Europe were poorl y rec ognizcd in the carly 1970 s. In th e mc antime, ou r kno wl edge on s na kes inhabiting the western Palaerctic in the early N eogene has considerably

grown,

es pccially during the last IWO decades. Thanks to th at, it is no w possible to identify most of the fossils originall y descnb ed by Ant uncs & Rage to the gen eric level.

Th e oph idian remai ns from the Portuguese sites were co mpare d with fossils coming from a numbcr of Euro-pean localiti es, in particular those of similar geological age (i.e.,lower/middle

Mioc ène

transition). Th csc locali-tics are follow ing (papers dcscribi ng sna ke fauna s are given in parenth èses) : C ôrcolcs in Spain (MN 4) (Alférez

& Brea 198 1); Agramon in Spai n (M N 4 ) (unpublis hed obse rvatio ns); D olnice in Czechia (M N 4) (Sz yndlar 19 87); Petersbuch 2 in Ge nnany (MN 4) (S zyndla r &

Sc hleic h, 1993) ; Ob erd orf in Aus tria (MN 4) (Szyndlar 1998); Vieux Collo nges in France (MN 4/5) (Ivanov 1997, Szyndlar& Rage 1999).

10_{Congresso sobre}

0Ccnozôico de Portugal

DESCRIPTION OF THE M ATER IAL

Fa mily BOIDA E

Cf.Bavariaboa sp.

(Fig. 1)

littl e probable (apart from lacking fossil evidence ofsuch a possibility). This snake

is

therefore supposed

an

immigrant that appeared in Europe perha ps yet in the Late O ligoc ène immed iately after improve ment of th e cl imatic conditions (Szyndlar& Schleic h 1993; Szyndlar& B ôhme 1993) .

1974 - Boidae: Boidé indét. Antunes& Rage, Tab le 1 Family COLUBRIDAE

(p.59).

Matcrial

Two mid- trunk verteb rae from Quinta das Pedreiras, Va2 loca l unit, MN4.

One vertebra was desc ribed and figured by Antunes

&

Rage (1974 : 53, fig. 3) (F ig. 1 A·E in the present paper); the other vertebra, partl y da maged (Fig . 1 F·G), was pre-viously not studie d.

Both vertebrae display fcature s characteristic for the Boo idea ("" family Boi dae s.l .), among othe rs they are strongly built and possess relatively very short centra and red uced pre zygapophyseal processes. By their ove rall morp hology, the vertebrac are most similar to those of the extinct European ge nusBavarioboa .Close simi larities can be observed in relatively large absolute dimensions of the vertebrae (wh en compared with the Erycinae, another Iineage of booi d snakes widespread in the European Neogene), stout morphology of the entire verteb ral bod y, w eakly m ark c d inde ntati o n b etween pr e- and postzygapophyses, vaulted neural arc h, and strongly built haemal keel (Szyndlar& Schleich, 1993). Preci se taxo-nomie allocat ion ofthe vertebrac from Quinta das Pedreiras is however not fully possible , first of ail because of the scantiness of the material; on acco unt of that the generic name Is prc ceded by the particlc "cf."

Com ments

Present studies (part ly unpublished) indicate that the genusBava rioboamay have been widespread in Europe in the period bet ween the late Oligocene (M P 27 ) and the m iddle

Mioc ène

(MN 6) (Szyndlar

&

Sch leieh , 1993; Szyndlar, 1998; Rage& Szyn dlar, in prep.). The type spe -cics (and the on ly described spe-cics ),Bavarioboa hermi,

was origina lly re ported fro m the lo wer Mioc ène o f Petcrsbuch 2 in Gennany (Szyn dlar & Schlei ch, 1993). Snakes coming fro m oth er Europ ean localiti es di ffer slightly from the type mater ial.

Ba varioboarepre se nts the family Boidaes.s. (""

sub-family Boinae or boas ) as indicated by the presence of paracotylar fc ramina in a part of vertebree coming from th e type locality. Occurrence of boas in the lower and mid dle Mioeene of Europe is astonishing, particularly co nsidc ring the d istrib utional pattern of their living rela-tives (today occ upying the trop ical America, Madagascar, and so rne West P ac ifie is lan d s) . Conside ring th at

Ba variob oawas a rela tively large and certainly

non-bur-rowing snake, its possib le ancestry among Eu rop ean autoc hthonous Eoce ne Boidae and, in consequ ence, its surviva l despite the severe conditi ons o f the OIigocene is

Cf.Colubersp.

(Fig. 2)

Material .

One mid-trunk vertebra from Amor (Leir ia), MN5.

Th e vert cbra was not studi cd by Ant unes & Rage (1 974). Owing to the pres ence ofa haemal keel (instead ofhypapop hysis), the vertebra is charac teristic of the "non-natricine" Colubridae. Th e verte bra belonged ta a large snake; although its condyle is partl y damaged and there-fore precise measurements are impossible, the centru m length most likely reached the value of 7 mm approxi-mate ly. Despit e the poor preservation of the vertebra, its morphology (in partieular the shape o f the haemal keel and mo derately elon gate centru m) alon g with the rcla-tivc1y large size indicate th at it may have repre sen tcd the living genusColuber ,For the same reasons as in th e case

ofBa varioboa the gene ric allocation of the discussed

co lubrid vertebre canno t be fully dcmo nstrated; on aecoun t of that its generic name is preceded by the part icle "cf."

Com ment s

The snake from Amor is most similar to Coluber

do lnicensis and

C.

casp totdes ,both extinct spec ics

de-scribed from the lower Miocene of Dolnice (Szyndlar, 1987) and Petersbuch 2 (Szyndlar

&

Sc hlcich, 1993), re-spectivcly. Thcse two fossil taxa, reportcd later atso from other olde r and coevallocalities (among others in Czec hia and Austr ia: lvanov 1997; Szyndlar 1998), may have ac-tually repre sen ted a single species. Both wcre prob abl y closely re lated to

C.

casp ius ,inhab iting to day southeast-ern Euro pe, and may hav e repre sented an evolutionary lineage lea ding ta the recent species.

Col ubridae indet.

Material

One

mid-trunk

verte bra fro m Q uinta das Ped reiras; one mid- trunk vertebra frorn Qu inta do Pombeiro, Va2 local unit; MN4 .

Two sma ll vert ebrae from Q uinte do Pornbeirc were desc ribe d by Antu ncs & Rage (1974 , p. 57) as follo ws: "de ux très petites vertèb res apparti ennen t aux serpents, elles ne sont pas d éterminables". Both boues are strongly damaged and o n acc o unt of thaton e of them is indeed unidemifi able. The othcr vertcbra ho we ver rcprcsented no dc ubt a memb er of the fa mily Co lubridae. Th e presence of a haemal keel suggests a "no n-natricin c" Co lubridae .

T he vcrte bra from Qu inta das Pcdreir as was c harac-terized by a relatively elonga te centru m, whereasthatfrom Quin ta do Po mbeiro was pro vided

with

a rela uvely shor t centrum. Most likely,bothfoss ils represen tediwodifferen t species.

A single verte bra of an unidcntified Co lubri dac fro m Universidadc Cat ôlica ( MN 3) "eColu brinè» à vertèbres

relat ivement allongées", according to Antun cs & Rage (197 4, p. 52) was not availa ble to the presen t study.

Fa m ily VI PE R ID AE

Viperasp .

1974 - Viperidae: Vipérid ô indét. An tunes & Rage, Tab le1(p. 59).

Mater ia!

One rmd-trunkvertebra from Quintedas Pedre iras.

Vipcrid sna kes can be easily distingu ished from o the r ophidiens bea ring hyp apc physcs thr o ug hout the thoracic po rtion of the column o n the ba sis of sevcral fea tures , amo ng others by

having

straight hypapophyscs, ven trally dircct cd par a pop hyse a l p roc esse s, and po s ter iorIy dcp rcssc d ne ural arches. T he vertebra fro m Quinta das Ped reiras (cf. Antunes & Rage, 19 74, fig. 4) , alt hough devoi dof pa rapo phys eal processes and hypa pophysis, is clearly referable to

vipcrs

based on the strong

flattcning

of its neura l arc h. It dis pla ys weil several charac ter istic

Ct ênctas da Terra (UNL),14

fea tures of the "Oriental vipers" co mple x of the living genusVipera :of the m, the most import ant are la rge

abso-lute dimension s and relative sho rtness of t he vertebral cen trum (Szyndlar & Rage , 1999) . T he cen tru m of the discusscd vertebreis 7.5mmlong and

it

isas long aswide. Vertebral ce ntra ofrnembcrso ftwoo ther co mplexe s of the gen usVipera ("aspis"an d"berus"g rou ps) are smaller and rela nv ely mo re elonga te.

Co mments

Large members of the ge nus

Pipera

("Orie ntal vipe rs" com plex) tirst a ppeared in Euro pe at the e nd o f lower Mio cene (MN4 )and sincc then they belonged to corn-monest Europ ean sna kes in a consi de rable part of the con-tinent. At the turn of the Pliocene the "Orie ntal vip crs" bccame cxtinct alrnost entircly within their European range, mainly beca use of the c1imatic deterioration. Today, tbesc snakes inhabit pr încîpally Middle East and northem Africa, whereas in Europe they oeeur in so utheas temrnost skirts of the con tinent only.

CONCLUS IONS

Ccmparcd with othe r Euro pea n fau nes o f simi lar age, the Po rtuguese snakcs fonn an asse mblage hig hly cha rac-tctis tic fo r th e lower/middle M ioeene transi tion. The ophidien fauna from Por tugal is not as dive rse as t he fa unas desc ribed from coevallocalitics of ot her Eu rop ean countr ics, in particular France, Germa ny, and Czec hia. but this impovc rishmcnt no doubt res ults from the scantincss of the available ma te ria l rat her th a n from a ny o ther reasons. Interestingly, the sna ke assemb lage from Portugal least resembles fa unas co ming fro m the near est lccalities: Cércoles and Agra mo n in Spain and Vieu x Coll onges in France (cf. Table) .

Th e lower/middle Mio cc nc transi tion (MN 415)is a distinct "border

line"

in the co mposi tion o f sna ke

faun as

in Europe (Szyndl ar& Schleic h, 1993; Szyndlar&B ëhmc,

TABL E

Comparison of the occurrence ofBavartoboa, CO/liber(cf.C.dolnicensisor cf.C.caspioides),andvipero(t'Ortenut vipers" complex) in the Portuguese and other European loealities in {he lower/middle Mioccne transition period.

Bavarioboa Colub er Vip era

Amor

-

+

-Q. das Pedreiras

+

-

+

C ôrcoles

-

-

-Agram on

-

-

-Dolnice ?

+

+

Pcte rsbuch

+

+

+

Oberdo rf

+

+

-Vieux Collonges

-

-

+

N

~

~

Smm

c

./

:1

'1

~

~

_~

"

,

• c ' : \ : , • . ~:

.. .. 1 l '

"

i

, ; :"

G

"",",',>

~

~~~"1

~"' -

, ~ - - - .-": ':'

< '

~ I ~"~

,

-.-,î~ "

'

1.-

,:r;,

.'f ~~

\ ."

,. -a.

"

l '

,i:

\1

,>

I!~ ;

/IU/

~~

.

11

\~ /Î ' ! If ~ : '

,

-"~

,pJj:,:';

\

~ ,r

"

\1,".-"..

_{--- -}

' r:

'

"

B

(

,

" ,

Fig, 1 - Twc vertebree (A- E an d F-G) of cf.Bavarioboasp. from Q uinta des Peor etras. A · loft lateralvicw :F - right lateral view ; B - dorsal view ; C. G _ vent ral vicws; D •anterior view ;E -postcriorview,

e,

j

c, u

~

. ~

'0

~

o

~

[

o

.. . da Terra (UNL) , 14

Ctëncias

unu

ç

<

1° Congresso sobre 0 Cenoz6ico de Portugal

1993). Although a number of (usua lly s mall-sizcd) mem-bers o f thefamiliesCo lubrid ae andviper idaewere prese nt in E uro pe a lre a d y in th e Ol ig oce ne and lo wer most Miocène,res pectively. the ophidian faunawasstill demi-nated by pri mitive sna kes , main ly bo as.

At th e en d o f th e lo wer Mio c ène, a conside ra ble numb er o f newophidien taxa invaded Europe. Th e mos t charact er îstic (and at the sa me lime most co mm on) ele -ments o f the migrations we re large-sized sna kes bclo ng-ing to three most ad vanccd op hidi an familie s:Coll/ber

( family Col ubri dae ), "O rien ta l vipcrs''(vip eridae). and co bras of the gen us Naj a(Elapidae), the latte r abse nt in the Po rt ug uese materia ls. The inva s ions o f "O riental vi-pers" and cob ras as weil as other the rmop hilous snakes (inparticular Pyt hon) may havebeen corrclatcd withthe t he rma l max imum ob ser ve d in th e E uro pea n c1ima te aro und the lower/m iddle M ioc ene tran s itio n (Rage in Dem arcqet a /.,1983).

Following the arr iva i o f new sna kes at the end o f the lower Miocène, "arc haic" co mpon e nts o f the E uro pean

R E F ER E ~ CES

snake fauna (ma inly boas. includi ngBavarioboa )became ra re in fos sil rnateri als and subs eq uen tly d isappeared c o mple te ly in t he middl e Mioc ène. lnterestingly, an o verw hcl ming maj o r it y o f " mo d ern" cle me nts of the Europ ean sna kefauna, inh ab itin g Euro pe from the midd le Miocène onward, we re closelyrelated 10 speci es living rece n tly, a lt ho ug h no t ne ce s s a r i ly in the E uro pean co ntinent.

ACKNüWL E DG M E NTS

1am deeplygrateful 10 ProfesserMiguelTelles Anru nes (U niversida dc Nova de L isbo a) fo r the loan o f the mate-rial to st udy as weil as fo r his great hosp italit y d uring my vis it in Portugal in May 1999. T he stud y wa s. suppo rted by the grant 6 P04C 073 14 of the Committec of Scie n-tific Resca rch of Pola nd .

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Antunes, M.T.& Mein, P.( 1981) -Vertébrés du miocène moyen de Amor (Lciria). importance stratigraphique.Ctënctasda Terra

(UNL),Lisboa,6: 169- 188.

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Antunes, M.T.& Russell, D.E.( 198 1) -Legisement de Silveirinha (Bas Mondego, Portugal). La plus ancienne faune de vert ébr és eocènes en Europe,C.R.Acad.Sci. Paris,293,sér.D:[099- 11 02.

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paléogécgraphiques.Cretaceo us Research ,London, 2:65-84.

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des Sciences,Paris.122 (5): 25 1·252.

Szyndlar, Z.(1987 ) -Snakes from the Lower Miocene locality ofDol nice (Czechoslovakia).Journal

0/

Vertebrale Paieontology. Lawrence,7 ( 1): 55-7 1.

Szyndlar, Z.(1998 ) · Vertebrates from the Early Mioccne lignite deposits of open-cast mine Oberdorf (Western Sryria Basin. Austria). 3. Reptilia 2: Serpentes.Annaten des Naturhtstarischcn Museums in Wierl ,99A: 31-38.

Szyndlar,Z.&B ôhme.W.(1993 ) -Die fossilen Schlangen Deurschlands: Geschichrcdcr Faunen und ihrer Erforschung.

Menenstetta,

Bonn.3: 381-431.

Szyndlar, Z.& Rage, J.C.( 1999) ·Oldest fossil vipers (Serpentes: Viperidae) from the Old World.Kaupia,Darmstadt,8: 9-20.

Szyndlar. Z.& Schleich. H.H.(1993) ·Description of Miocene snakes from Petersbuch2with comments on the lower and middle