A C T A Vol. II
I' ,.\ L ,\ a 0 N T 0 ".L ,0 G I C A
1957
JULIAN KULCZYCK I
I' 0 L O N I C. ,\
No. 4
UPPER DEVONIAN FISHES FROM THE HOLY CROSS MOUNTAINS (POLAND)
Abstract . - The present paper deals with fos sil fish rem ains (Placodermi, Elasmo- branchii) from the Upper Devonian of the Holy Cross Mountains. The followi n g ne w fo'rms have been described: Mal ero st eus gori zdroae n. gen., n. sp.; Tomaioste us flrossi n.gen., n. sp .: Dinichthys denisoni n. sp .; D. ceterus n. sp.; Titanichthys ko- ilowsk ii n. sp. , Deveonema obrucevi n. gen., n. sp.; Operchallosteus vialowi n. gan..
n. sp. ; AUenacanthus malkowskii n. gen., n. sp .; Sentacanthus zeli chowsk ae n. gen., n. sp. The presence of Dinic hthys pusrutosus, D. cf. tuberculatus, Pachyosteus bu tia. H%nema radiatum, Anomalichthys ingens , Plourdosteus sp., Oxyosteus sp., Steti- osteus? sp., Ctenacanthus sp., as well as of som e detached teeth of Clado dus an d Dittodus, has been recorded. On the base of the inv estigated materi a l the au t h or agrees with the opin ion s postula ting that in Bra ch ythoraci there ha s occure d the disappearance ot dentine and its substitution by osseous tissue. In the brachytho - racids this process had taken place at a considerably ear lier evolutionary sta ge than in the Crossopterygii and the Dipnoi and it had. more over. progress ed farther, having affected the jaw denticles too. The structure of the paraspheno id in genus Pachyosteus, problems relating to the position of the gill slit, and changes in the outline of bones during ontogeny are discussed and some cursory remarks on the systematics of Brachythoraci are given. The final chapter contains notes on the stratigraphic distribution and geogr a p h ica l range of the described cra ch y th or a c id forms.
INTRODUCTION
This paper is concerned with .placodenm remains from Frasnian and Famennian deposits in the Holy Cross Mountains.
In accordance with information published by J. Czamocki (1947), tW:J sedim en t ati on zones may be differentiated within the region of the Holy Cross Mountains. Their boundary line runs ap prox im ately con for mably to the axis of the Kie1ce syncline. The northern Lysa Gora region differs from the sou th ern Kielce region in more complete development' of the paleozoic series, in facial differences and in considerably greater thick- ness of sediments which are frequently of Flysch character.
All of the Upper Devonian fish material has been recovered from the Kielce region, namely from the localities of Wietrznia, Psie GOI1ki and Kadzielnia, and from the village of Galezice lying south-west of Kielce .
ImmlHI
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rLLL.aDevonion \.,.../ w.etrzruo
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r.L..L.J depos irs
Rutka - - - - .
Fig.1. - Dis tri bu tion of loc a li tiesof fish rem a ins fin ds.
Geology simplified. after a ma p by J. Czarne cki. Scale 1:100000.
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UPPER DEVONIAN l"I SHES 287
In the adjacent hills of Wietrznia and of Psie G6rki the Frasnian beds are similarly developed. They are represented here by layered limeston es and thin layers of sh ales. The follow ing three horizons have been diffe- rentiated by Czarnocki (1947 and 1950; see also Rozkowska, 1953) on the recorded brachiopod fauna:
Upper Fras n ian -" horizon III with Hypothyridina cuboides an d Man- ticoceras intum escen s,
Middle Frasnia n - horizon II with Hypot hyridina coronula, Lower Fr asnian - horizon I with Hy poth yridina procubo ides.
The specimens of fishes have 'been recovered Irorn all Frasnian hori- zons iJn the Wietrznia hill. In Psie G6r1ki the fishes have been yield ed by horizon III only.
In the Kadzielnia hjll are developed the three Frasnian horizons and a considerable part of th e Famennian. The Lower and Middle Frasnian beds cons is t her e of reef lim estones. Fish re m ains have been found in Upper Frasn ian and Fam ennian beds only. The Upper Fr asn ian here is de veloped as thick bedded limestones with Hypoth yrid ina cubouie s and Manticoceras in tumescens. The Low er and Upper Frasnian con sist of shales and marls with a fauna of cephal opods represented by the genera Ch eilo ceras and Tornoc eras.
In the fourth locality situated at the village of Galezice (about 15 km to the south-west of Kielce) there ar e no Frasnian or Lower Famennian beds. Upper Fam en nian beds , reduced to a thickness of 3 to 4 m, rest di- rectly on the Givet ian . They are represented by limestones from horizons cont a in ing Prolobit es, Plat y cly m enia, Ort hocly m enia, Goniocl ymenia, and Wocklumeria, the latter underlying Car bon ife r ous deposits.
... The material desc r ib ed in th e present paper
.
is composed of two different collections:1) the specimens collected by the 'la t e J. Czarnecki before the war and pa r tl y destr oyed throug h war activities. This collection is housed in the Geolog ical Institute (I. G.) in Warsaw;
2) the sp ecimens collected by ·th e lat e Prof. Z. Gor izdro-Kulc zy oka and by the pr esent author between the years 1947 to ).952 on beh al f of the Muzeum Ziemi (Museum of the Eae th ) in Wars aw . Work at further enla rgement of the collection was con tinued by the wr iter during 1953 to 1955 on beh alf of the Paleozoological Ins tit ute of the Polish Acad em y of Scienc es in Warsa w. This coll ection is housed in th e Mus eum of the Earth (IVI. Z.) in Warsaw.
The material was mostly prepar ed by treatment in acetic acid and .satu r at ion in paraffin. Before being photographed the specimens were
whitened with ammonium chloride.
288 JULIA N KULCZ Y CKI
The labor atory work has been carried out in the yea rs 1953- 1956
,at the Paleozoological In stitute of the Polish Academy of Sciences in
Wa rsaw . Throu ghout the in vestigation most helpful ad vice an d assistan ce were given to the writer by the Head of the abov e men tioned Institute , Prof.Roman Kozlowski. In the course of the field work the most fr ie ndl y kindness and he1p were shown to the wri ter by the Managers of the Museu m of the Earth - Prof. 81. Malkowsk i and Pr of. A. Ha'lickD.
Dr. M. Zelichow ska , ch ief of th e Dep artment of Documenta t ion of the Geolog ical Ins titu te in Wairs aw, has provided the autho r witlh the OIPiPOII'- tuni ty for stu dying t!he specimens in her cha rge.
In 1955 an d 1956 the au t ho r spen t two mon ths at the Geol.-Paleonto- logi cal Ins titute of the Humbol dt Un ivers ity in Berli n. Prof. W. Gross has prov ided the author with the Iacilities for study in g at this In s titute and offered very use f ul criticism. Much valu able in format ion and advi- ce was obt ained by the writer, in the way of correspond ance, fr om Pr of. D. V. Obruche v of Moscow and Dr R. H. Denison of Chicago.
Miss A. Illner , the libr arian of the Paleontologi cal Institute of the Hum- boldt University in Berlin, has taken pains in su p p ly in g the au t h or with th e req u ired litera ture. The accom panying pho tog raphs ha v e been take n by Miss M. Czarnocka. The paper has been translated by Mrs. J. Hum- nicka.
To all these person s the writer wis hes to express his de ep es t gra- titude.
DES C RIPT IO N S· Order Arthrodir a Infraorder Brach ythorac i- Genus Pl'ourdost eus 0rvig , 1951
Plourdost eus sp .
(pI. I, fig. I, 2)
Mat eriaL - A fragmentar y posterior ventro la te ral and a complete mar ginal (pI. I, fig . 1). These tw o eleme n ts were found lying beside one ano ther on a small rock fragment and displa y a sim ilar ornamen ta tio n pattern suggest in g their appur te nance to the same in d ivid u al.
Description. - Pos terior vent rolatera l relatively la rg e, the preserved frag ment bei ng 38 mm long and 28 mm wide . Its an ter ior later a l por tion sh ows the base of a brok en off proces s, wh ic h in th is genus is commonly connected with the poster ior la t eral. The ou ter surface dens el y cover ed ,by minut e tubercles, somew ha t larger alon g the ma r gin, more so in the:
posterior portion. The associ a ted marginal is markedly sm al l. Its shape (pl. I, fig. 1) indicates th a t it was not united with the central. th is being
UPPER DEVONIAN FISHES 289
a characteristic fea ture of genus Plourtiost e us. The cou rse of suture with' the postorbit al and the paranuchal show the same inde ntu res as in Plourdosteus trau t sch oldi (East ma n) (Obru ceva, 1954, fig. 1), except for the side edge bein g more arched so that on the whole the marginal is more qu adrangular. The width of this element measur ed from the point of ju nctu r e with the pos torbital and the paranuch al is 15 mm. The same is its maximum leng th measured normally to the line.~f the prev ious dim ens ion. The sensory line groove transversing the marg in al produces a ra ther sharp bend from which bran ch es off a blind ramification. As compa r ed with Plourdost eu s tra u ischol di this rami fica ti on is placed mor e an te r io rly and has a more distinc tly late r a l direction . Judging from the shap e of the margin al the head sh ield may be supposed to hav e been mark edly short, with its posterior side corners ex te nding far to the sides.
The lack of a margin join ing the cen tral refers this specimen to the genus Plourdosteus.
In the sa me bed as the above mentioned specimens was also found the left infragnathal (pl. I, fig. 2) which, perhaps, may have belonged to the same form. Its en t ire leng th is 34 mm, of which 16 mm'are assign ab le to the functional an ter ior portion. The pos ter ior "blad e" is fairl y broad, at taining cen tr a lly a width of 8 mm. The upper margin nearly rectiline ar, wh ile the lower one is gently arcua te. On the outer sur fa ce the lower and the posterior por tions are clearly separated from the sm oo ther, upper -front portion; the la tt er passes in to the ante rior functional por tion of the infragnathal. Du r ing the life -time this had pr ob ab ly been cov ered by the mu cous lin ing only. Both the low er and upper margins of the functional portion are damaged, but it seems doub tless that the la tter was pro vi ded with a nu mber of den ticles. Tw o of these are preser ve d within the symphyseal part. Two such complete denticles are also observab le at the back of the functional portion. They ar e con ical and 2 to 3 mm in height. At the base of each of them the r e is a slig h t convexity on the ou ts ide of the jaw. Thes e convexities reveal that: in the functional portion there were five such den ti cles over a di- st an ce of 7 mm.
Occurrenc e.- The Frasnian, horizon II, Wietrzni a hill in Kielc e.
Brachythoraci gen. et sp. indet. (a) (text-fig. 2; pl. I, fig. 3 a-b)
Mate1·ial. - A median dorsal (pl. I, fig. 3 a-b), in a fairly satisfactory sta t e of preservation, has been recovered from th e same beds as the above described specimens.
Description. - It is elongate , being 41 mm long and about 28 mm wide. Transversally it is rather strongly arched. The maximum width is
Ac t a, Palaeontologlca Polontca - Vol. IIJ4 l~
290 JULIAN KULCZYCKI
Fig. 2. - Brachythoraci gen. et sp. indet , (n):
longitudinal section of the media n dorsal with desc ernible crestoutlina.
atta inedat the anterior, ar cua te margin.The side marg ins ar e firstgently concav e and then convex, running obliq ue ly posteriorly towards the median part to converg e at a nearly right angle. The ou ter surface is densely covered by minu te tubercles arranged on the circumferenc e in con c en tr ic rows . On the ventral surface the hin d portion of th is element
is
lim ited from the front portion by an arched ele vation running brans- versally at a distance of 8 mm from th e hind end of the median dor sal. Medially this elevation constitutes the rounded base of the cari nal pr o- cess. This base continues anteriorly into the crest running over a distance of 13 mm. The descr ibe d median dor sa l with a br ok en off crest may be taken for this elemen t of Cozcost eu s or of Plourdost eus but lacking the hind spin e- -like process , as is the case in Coccost eus jletti (Watson, 1932). However, the crest (fig. 2) preserved in the cast ascends ver y gently to the hind, in opposition to what we observ e in these gen era.It attains its maximum height of 6 mm very near the base of the carinal process. The latter descends at an angle of ca. 70° in relation to the median dorsal blade and basally shows a sp oon -lik e imp r ession . Thus, in what the shape of th e carinal process and of the crest is concerned , our specimen is more like genus Pholidosteus, differing from it in smaller height of the crest and in a terminally pointed hind end of the crest. Hence, the carinal process not only did not protrude beyond the posterior margin of the element, as is the case in Pholidosteus, but was deeply concealed unde r it. At the present mom en t: th e systematic position of the studied median dorsal may be only tentativel y estab lished, although it is !possible that we are dealing here with a new form.Occurren ce. - The Frasnian . hor izon II, Wietr zn ia hill in Kielce.
Genus Maleros teusI '11. gen.
Diagn osis. - Brach y thor aci with head shield broad, with rounded side marginssep arat in g the descend ing later al portion s fr om the flattened vau lt . The large orbital cavity is bounded by the su bor bi tal, preorbital and postorb ital. The structure of the cheelkpart is as in Pholidost eu s or Brachyosteus. Postpineal opening lacking . The jaw appara t us is of the crushing type. The infragnathal has a mod erately large cr ush ing surface of the upp er margin an d a tooth-like process at the fron t of the func- tional portion. The posteriorsupragnathal is broad,with a lateral process
t The generic name is an all us ion to the crushin g jaw ap p a ra tu s, being deri- ved from the Greek p.aJ' Epoa, meaning crushing.
UPPER DEVONIAN FI S H ES
and a well dev elop ed crushing surface prov ided wi'th twotubercles : one plac ed more or less medially , th e oth er at the top of the la ter al process.
The ant erior supragnathal of the ca tchin g type atta ched to a tooth- like process behind which mesiall y the re is an depressio n toaccomodate the tooth-like infragnathal process.
Rem ark s. - This genus is monotypic, er ect ed to include Malerosteu3 gorizdroae n . sp. In the disposition of the skull bones this Iorrn resembles Pholidosteus from which it differs in the stronger development of the crushing jaw apparatus bringing it closer to Mylostomidae and still mQ;I'~
so to Din om y lostom a. From the latter genus, however, it differs in the less developed infragnathal crushing surface, a lower and more consp i- cuously,limited hind portion of this element and in diff er en t pattern and degree of development of the posterior supragnathal tubercles..
Malerost eus gorizdroae2 n. sp.
(text-fig. 3- 6; pl. I, fig. 4- 7; pI. II; pl. III, fig. 1-3),
Material. - .A large skeletal fragment of one ind iv id ual, fou n d in the Psie Gorki hill. It comprises the preorbitals, su b or b it al, marginal, paranu ch al, infragnathal, posterior supragnathal, anterior suprag na thal, parasphenoid as well as fragments of 'th e dermal and endocran ia l bones , The suborbital and postsuborbital found in the Wietrznia hill are refe- rable 10 the same species.
Holotype. - Incomplete head shield and the anterior dorsolateral of one in di vidu al (M. Z.) (pl. I, fig. 4-7; pl. II).
Diagnosis. - Malerosteus gorizdroae is thus farttie on ly kno wn spe- cies of this genus so th a t the specifi c and generic diagnosis are the same.
We may add her e th at' our specie s is characterized by an ornamen tation pattern consis ti n g of round ed tuber cl es of va rious size, the whole rathe r large, particularly so in the hind part of t'he head . These tuber cl es are arr an ge d dens ely and ir regularly.
Description. - Th e preserved !parts indicate that they bel on g to a broad-headed form, with a blun t snout and dist in ct ly ma rk ed side edges ("Dorso-l a ter alkan ten " of Gross , 1932), produced by the angular disposition of the lateral an d dors al parts of th e skull. At the front 'of the orbital fenestra this angle is about J.20", while in the portion cor res- pon di ng to the paran uc hal it is as much as 130 to 140°. Fr om a side view this sk u ll rese m b les th a t of Pholidosteus friedeli Jaekel as recons tr u cted by Jaekel (1907) or by Gross (1932). The sim ila r it y also concerns the pos ition and relative dimensions of tihe orbital fenestra with a diamete r
! This species is named in honour of the late Prof. Z. Gorizdro-Kulczycka who initiated research work on the Devonian fishes from the Holy Cross Mountains.
292 JULIAN KULCZYCKI
of 60 mm in the specimen here considered. Similarly as in Pholuiost eus and the majority of brachythor ac ids fr om Wild un gen the marginal here ex te n ds into the cheek area , while the su borbital and the postsuborbital are not fr ee, th is being a feature char ac teristic for example of Dinichthys and Coccos t eu s. The entir e oute r surface is covered by rel ativel y larg e'. roundish tubercles var yi n g in size fro m 0.5 to 2 mm, on the who le larger in the posterio r part of the head. Where the su pe rficial layer of the , bon e has been worn off, t'he tubercles are considerab ly smaller, sug ges- ting tha t their size was dep enden t on dimensions and age of the ind ivi- dual.
The centr al is preserved as a rather small fr agment of the anterior process united with the mes ial ma rgin of the right preorbital, This pro- cess was less slen de r than that in Pholidosteus friedeli Jaekel.
The pineal has been pres erved as frag me n ts lying quite close to the an t er ior process of the central indicating that th ese two bon es touch ed each other. The pineal foramen is open. A sh allow groove is indicated at one side of it only, this asy m me tr y suggests the presence of another pineal foramen , as is the case in Pholidosteus fr iede l( Jaekel (Stensio.
1934a).
The preor bi tals (IPI. II, fig. 1) are broad (70 mm), their length is one and a half times as 'large as the width, being over 100 mm. The mesi a l margins have been destroyed but the fad of th e .preservation of the pin eal and the central suggests tha t the preorb itals of both sides were not in contact. The posterior por tions of thes e bones dorsally overl app ed the centrals and the postorbitals, The ant er ior part of the preorb itals forms the anterior marg in of the orb ital cavity. Itis provid ed with a not ch. From the top and inside of the orbital cavity a groove runs downwards onto the outer su r face terminating within the an t eri or angle of the or bit al fenestra. From the end of that groove, another, less di;- stinc t ly marked , with a number of foramina , ru ns ver t icall y , an d ex - tends to the su p raor bital line ("preorbital", according to the terminology of Heintz, 1932), without, however, reaching it. The supraorbital line is ind icate d ca. 5 mm above the eve n tu al point of juncture with the prolon- gat ion of the mentioned groove. The absence of traces of the supraorbital line below that sector cannot be ascertained quite doubtlessly owing to the bad state of pres ervation of that portion of the surface. In the anterior part of the preorbital, the supraorbital line runs closer to the margin of the orbital fenestra than it is the case in Pholidosteus friedeli. On the ventral side a crest is visible on the preorbital, corresponding to the boundary of the "lateral consolidated part" (Heintz, 1932), separating the median part which coats the endocranium from the lateral part.which constitutes the vault of the orbit.
UPPER.D E VO N I AN FISHES 293
The suborbital (pl. II, fig. 1, 2) is pr ov ided with a high posterior blade (over 55 mm) whose preserved portion constitutes the margin of the orbital fenestra and with a slender anteri or part , the "hand le"
of Heintz. In this "handle " we may distinguish the upper ornamented pa r t and the lowerlistconstituting what Hein tz (1932) calls the "to ngue shaped part of handle". According to Stensi6 (1934a) it is connected by its lower edge with the palatoquadrate . As is th e case in other Brachy th or aci, bot h the se parts are sepa ra te d here too by an in cis ion which Stensio (1934a) call s "inc isu ra maxillaris buccalis". From the mesial side of the an ter ior
par t of the su borbit al runs a broad horizontal list limiting the or bit at the base. The infraorbital canal runs on the outside with the fore-pa rt of the supramax illar line arising somewhat above the point' of ju nction of the postorbit al and su bor bital par ts . This branching is particu la r ly conspicuous on the specim e n of the su bor bital from Wietrznia (pI. II, fig. 2).
The postsubo rbital (pI. III, fig. 1) recorded from the same beds of the Wietrznia 'hill belongs to anoth er individual, pr obably of larger dimen- sions. In the antero-posterior direction an d normally to it the postsuborbi- tal is curved, it's.con vexi ty being dir ect ed outw ards. This is associate d with the box-like shape of the shield characteristi c of the here studied Iorrn, though to a smaller degree than it is of Pholidosteus . At the base of the an t er ior part , the postsuborbital is pro vi ded with a process wh ose margin is overlapped by the suborbital. The anter ior a:nd upper marg ins limit a proj ection which most likely penet rate betw een the su b orb i ta l an d the postorbital. The 'length of this elemen t measur ed a'long its free margin is 90 mm. Measured normally to it the height of the ou te r orn a men te d surface is 55 mm.
The marg inal (fig. 3;pl. II, fig . 4) is preserved on the righ t side only.
From behind and t'op it bounds the paranuch al, from the fron t th e pos to rb ital . It 'is elongated, with the long er ax is somewhat ob li q uely tr aversing the head sh ield. Its low er en d considerably approaches the posterior mar gin of the skull. Neverthel ess, since this por t ion has not been pres erved, it cannot be ascertain ed whether the ma r g in al reached to the free margin of the head shield or was separ a te d from it by the postmarginal, as <it does in Pholidosteu s. Near t'o the upper ma-rgin ad j acen t to the paranuchal this bone is traversed by the sensory line groove which branches off from the side downwards somewhat posterior- ly, similarly as is sh ow n in Jaekel's reconstruction of Pholidosteu s.
The width of the marginal ranges from 32 to 41 mm, the length of th e preserved part: is 50 mm.
By its shape the paranuchal (fig. 4; iPI. II, fig. 4) closely resembles the correspondjng -elemen t in Pluslulosteue and anteriorly it was most
294 JULIAN KUL CZYCKI
Fig. J. - Maler ost eus gorizdroa!? n. gen., n. sp.:
diagrammatical reconstruction of skeleton, side view;
missing parts dotted. ADL anterior dorsolateral, IG in- fragnathal, M ma r g-nal, PN pa ranuch al , PrO preorbital.
PSO post suborb ital.
likely connected with tlhe postorbital thus separating the marginal from th e central. Similarly as in Jaeke l's reconstruction of Pholidosteus there are no traces here of the posterior portion of the occipital line (called so afte r the nomenclature of Gross , but by Stensio refer r ed to as the "po-
I
P9
Fig . 4. - Malerosteus gorizdroae n. gen., n. sp.: post erior margin of para nu ch al; to joint soc ke t,
pg joint process, x lateral edge.
sterior pit-line") , whose (presence in Pholidosteus has, however, been mentioned by Gross (1932 b, p. 14). The por tion forming a sheath for the postero-lateral ends of the nuchal (Heintz's "h ind thickening") is not so conspicuously ar che d ventrally as may be observed in Dinichthys. In consequence, the posterior la teral impression, as it is called by Heintz;
is not so clearly limited. At the sam e time, in Malerosteus we can distingu ish that: part which forms the joint th ickening. The joint socket
UP P ER DEVO NI AN l"ISHES
i~ relatively longer (31 mm) and narrower, and displays greater uniformity of diameter than in Dinichthy s, being here 7 mm laterally and 6 mm mesially. The low er and upper "jo in t processes" , as called by Hein tz , are no t developed . The posi tion of the top of the upp er process is marked by a rib rea ch ing her e to the margin of th e socke t. The glenoidal pro cess was short (15 mm as measur ed outs ide at the margin of th e ornamented paranuchal sur f ac e) and obliquely plac ed. It!s ou tli ne does not protrude bey ond the margin of the joint socket.
The i nf r agna thal (p l. I, fig. 7 a-b)i's fr-agmen t ary, but' with the functional part preserved on the left side. Its ante r ior symph yseal end is provided with a rather larg e tooth-like process, 10 mm high. Dors ally, beh in d it stretches the crushing surface, which is mode rate ly broad
(E mm fron t ally and narrowing post eriorly). It has a mesial impression to accommodate a tu b er cle presen t on the posterior supragnathal. The en tir e functional portion of the infragnathal is an almost perfectly flat, unifo r m ly thick plate. At its lower margin there is a groove for the mandibular line, running antero-rnedially. Its presence indicates that Meckel's cartilage was not in contact with the lower margin of the infragnathal, as has been figured in Stensio's (1934) reconstruction of Leiosteus, but that it occupied more mes ial position in relation to the in fr agnathal, The len gth of the functional por t ion of the infragnathal in Malerosteus is 62 mrn, the height being 24 mm.
The posterior supragnathal (fig. 5; pl. I, fig. 6 a-c ) is an elongated plate narrowing posteriorly. Frontally it is provided with a lateral process, as in Coccosteus, bu t without the vertical row of den tides.
The low er side has a fairly broad surface, convex throug hout, which, cor resp on d in g to the forrn of th is element, is o-homboidal and has a triangular excavatio n bounded by two diagonals. The exte r ior corner corresponding to the lateral process is provided with a minute tubercle.
A larger one is sit uate d more or less centrally, i.e. nearer to the mesial an g le. The anter ior mesial surface is conc av e, both vertically an d hori- zontall y agr eeing with the shape of the con tiguous su rf ace of the an te r ior su pr agnath al , The length of the posterior su p ragn at hal is 48 mm, the width 32 mm, when measured in the upper 'Part of the ele ment' from the apex of th e upper process, wh ich is her e almo st hor izontally placed, to the sid e margin of the lateral process. 'Dhe frontal- wid th of the crush ing su rface is 16 mm; maximum height, together with the tubercles, is 18 mm , of which 2 mm are involved by the mentioned tubercle.
The anterior supragnathal (fig . 5; pl. I, fig. 4 a-b, 5) of both sides have .been preserved, thou gh damaged. Th ey are in the shape of hor izontally curv ing plates, Along the curving edge is a rounded rcrest elong a ting downw ards into a strongly tooth-li.k~!process ] 0.mm in len g th .
291; JULI AN KULCZYCKI
Mesia lly, behind the men ti oned process, there is an excavation to fit a similar process of the low er jaw. Farther to the rear stretches a small flat area whi ch is-the ext ension of the crus h ing surface in the posterior supragnathal. The upp er porti on and the anterior margin are damaged in both specimens.
The heigh t of the anterior supragnathal cannot have be en much in ex cess of 22 mm (no t comprising the tooth-like process).The maximum attained thickn ess is 7 mm.
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, - - -
ASG ,
.Fig. 5. - Ma ler os teus gorizdroa e n. gen., n. sp. ; jaw app ar a t us : A upper eleme n ts, ventral view, B same , side view, C jaw app a rat us, medial view , D":E posterior supragna tha ls, ventral view , D Din omylost oma beech eri , E Mylostoma vari ab il e, ASG an te r ior su prag na tha l, IG inaragnathal , PSG posteri or su pragna tha l, pI lateral
process, posterior supragn ath al , mt middle tubercle.
UP PER DEVON I AN l"ISHES 297
The parasphenoid bel onging to this specimen has already been indiv id ual ly des cribed in a [previous note of the wr iter (Kulczyck i, 1956) ,as an elemen t of Br achythoraci n. gen.
The anterior dorsolateral (pI. II, fig. 3) is here incomplete, as mos t of the bones of this specimen. Th e senso r y line runs on 'the outsi de, reach ing to the hind marg in of th e bon e , Iperhap s even beyond it. The course of the lat eral line aiso indi ca t es th e dor sol a ter al marg in , along wh ich the low er and the upper parts of the anterior dorsol ateral lean against one another. The angle thus produced by them near the anterior margin has 140°, while posteri orlyit approaches'180° an dthe dorsol ateral edge disap pears. On the med ian si de, along the poste rior marg in , a fla t area is ind icated, overlapp ed by the pos t er ior dor s ol at eral. On the anterior dam aged edge there is an inconspic uous thickening suggesting that the cond yl e was not dev elop ed very strong ly. The length of the pre- served par t is 85 mm. The thic k ness at the anterior marginis up to 18mm. As is shown by its description , the head shield of Maleros ten~
displays marked resemblance to that of Pho luiosteus. It is to this genus tha t Gorizd r o-Ku1czyc k a (1950) has referred Iragrnents of head shield from Czarnecki's collec tion. Never th eless, the evidence acq uired on a mor e complete spe cimen, particul arl y that from the cha ra cter istic jaw app ara tus, calls for the assignment of this Ionm to a new genus .
A spe cimen of the posterior me di an ventral bon e (f ig . 6; pl. III, fig. 3) in a satisfa cto ry sta te of !p,res ervat ion, found in the Frasnian of the Wietr zn ia hill, can only te n ta t ively be assigned to the same species. Its tubercul at ion pa ttern does not excl~de the possib ility t.h at this eleme n t is ref era bl e to gen us Mal er osteus whose range should in this cas e be shifted to the Middle Frasnian. Specimens of M. qoriztlroae from the Upper Frasnian , ho w ever, do no t exhib it a conc entric arr an ge- ment of tubercles , which is here qu ite conspi cu ous near the ossificatio n centre.
The IPost'erior medi an ventral here con sider ed (fig. 6; pl. Ill, fig. 2) is in the form of a larg e pla t e, 107 mm long and ab out 85 mm broad.
It is gen tly tr ansvers ely curved in di ca ting that the ven tr a l shield of this spe cies was slig h tl y convex. Anteriorly there is a small area, 12 mm in length and 32 mrn in width , to fit the anteri or median ventral. Fuirly large areas stretch along the side edges to be ove rlapped by the ventrolaterals. Further to the front are somew hat rais ed areas , about 60 mm in length on every side and about 8~ mm in width, overla p ped by the anterior ven tr olater al. At the back a lowered and sm all e r area is obser vable to fit the poste r ior ventro lateral. Its maxim u m wid th is 20 mm while the length is 58 mm. The fr ee area of the posterior median ventral, covered by tuberculation, has the ou tline of a cross with a blunt for e-
298 JULIAN KULCZYCKI
Fig. 6. Mal erosteus goTizdr oae? , post e- rior med ian ventra l. Thick continuous line - outline of free area in adult individ ual ; thin continuous and broken line - outline of free area in young individual; dotted line - outline of th e who le eleme nt in ad ult individ ual.
....
....
....~
-,
-.
....
......
arm, while the others are poin te d. Its tu berculat ion resembles that ch ar act eri sti c of M. gorizdroae.
The element described abo ve is in teresting since we can observe in the middle of its free surfac e an area dis tinctly limited posteriorly and exh ib it ing a fin er tub er cu la tion with a radial arrangement. This area most likely corresponds to the juvenile stage of the post erior median.
ven tr al plat e. Its out lin e in dicates th at considerable changesinthe shape of this ele men t mus t have occurred along with its growth. In a young individ u al it was sh or t, its ou tli ne bein g an almos t regu la r pentago n -, with gen tly concave margins. The i differences occurring between a ju- venile an d an adult specimen are so great as to mak e possible the assi gn- ment of the ir deta ch ed skeletal ele- ments to diff eren t taxonomic units. A nu chal (p l. III, fig. 2 a-b) in a fairly satisfactory state of preser - vat ion has been found in the same beds as thespecimendescribedabove. It has a similar ornamentation, con- sisting of coarse tubercles whose arrangement is concentric around the ossification centre only where they are of smaller size. Vent r ally, near to the hind margin a double sock et dis tin ct ly divid e d centrally is discer- nible. The partit ion th at divides it is broad anteriorly, narrowing dow n to the back. In addition a relatively low transversal rid ge occu rs her e , behind wh ich on the hind edge the re is a minute central pr ocess. The pr eserved frag ment is 40 mm in length alon g the cent ral lin e and 73 mm broad along the hind margin .
Occurrenc e. - The Frasnian , hori zons II? and III in the Psie Gorki and Wietrznia hills.
Genus Tomaiosteus»n. gen.
Diagnosis. - Brachythor aci, with the head broad an d flattened, at leas t in the anterior part , and moderately large orbits placed near the
S The generic name from the Greek word tOf-latoa - "cu t ti ng" is an allu- sion to the cutting type of the jaw apparatus.
UPPER DEVONIAN FISHES 299
Fig. 7. - Tomaiosteus grossi n. gen., n. sp.; the pineal: A ventral view,
B dorsal view.
anterior end of the skull. The pineal touches the centrals and the rostral, thus completely separating both preorbitals. The jaw apparatus of the cutting type not too highly specialized, Posterior gnathal with preserved lateral process.
Remarks. - This genus is monotypic, erected to include Tomaiosteus grossi n. Sip. From other forms with a cutting jaw apparatus this genus differs in the presence on the posteeior supragnathal of the lateral process which is here, however, not so strong as
an
Coccosteus and similar forms. From the latter, Tomaiosteus also differs in a poorly developed upper process and in general outnine of the hind upper jaw element.Tomaiosteus grossi n. SIp.4 (text-fig. 7; pl. III, fig. 4, 5).
Material. - The preserved fragment represents an almost complete pineal, a major part of the preorbital, small fragments of the centrals and a satisfactorily preserved posterior supragnathal. An indeterminate endocranial fragment was also found together with these remains.
Diagnosis. - The same as for the genus, but also sculpture characteri- stics, consisting of irregularly disposed tubercles of varying size and with basal diameter of 1 mm or less.
Holotype. - Fragment of fore....part of skull with tJherposterior supragnathal (1. G.) (pl. III, fig. 4, 5).
Description. - Pineal (fig. 7; pl. III, fig. 4) is an elongated bone whose length measured medially,
without the portion missing in the specimen but together with the po- sterior process, is 40 mm. Dorsal, tuberculated surface 15 mm in length and minimum 7 mm in width. The pineal plate overlaps the centrals wedging in between their dorsal surfaces. In this way, when seenfrom the ventral side of the head shield, this process appears as a triangular element, half its actual length. The remaining free margins preservedin the specimen, have grooves fitting
the corresponding ridges of the mesial preorbital margins. At a distance of 25 mm from the apex of the medial posterior process is the minute
'( This.species is dedicated to Prof. Dr. W. Gross from the Geol.-Paleontolo- gical Institute of the'Humboldt University in Berlin.
,300 JULIAN KU LCZ YC K I
pineal foramen opening on the ventral surface of the'bon e in to th eipiriea l
:depressi on. This hollow is sharp ly limited by adistinct:ridge while.to the
.Ir ont it gradually passes inter the ventral surface of [he pineal plate .
It lis notewor th y that the pin eal for am en is placed somewhat laterally to the plane of sym metry indicate d at the bottom of the pineal foramen by a slight' elonga ted rib. This is also a sign that the pineal opening was origin ally paired.
The preorbital (pl. III, fig. 4) must hav e been very broad and almost flat. Its media n margin is arcuate, at first adjacent to the rostral. The preorbital was connect ed with tlhe latter by a nar ro w bu t rather long , transversa lly dir ect ed embayme n t in the an terior par t of the median margin . The orbita l margin or the preorbital is not' pr es erved. The lim it.
however, of the orbital vau lt, visible fr om the ventral sid e , where we can also see a fragmen t of the postorb ital, sugges ts th a t the or bits were relativel y sm all, most likel y much less than 45 mm in diameter. In the an terior medi an port ion of the orb ita l vault is a funnel-like impression.
Abo ve lit in the crest centrall y lirnining the vaultin g, a notch amd a groov e occu r. probabl y serving as a duct for a nerve or vess el branching.
The preserved fragmen t of the central indic ates th at this elemen t was more than 60 rnm broad in the an terio r par t. ThE ante r ior marg in of its lateral por-tion lis nearly straig h t, trans ve rsa l to the cr an ia l ax is . :.vre 5iall y it develops a broad triangular process, abo u t 20 mm high and (1,';
much basally broad. 'I'his proc ess fits betw een the preorbital and the posterior pmeal proce ss .
The posterior supragnathal (pl. III, fig. 5 a-b) is of the cutting type with a fairly sharp Iow er edge. It is in the form of a pla t e, 43 mm long, mesially divided by a vertical rid ge into the hind portion 27 mm in length and the front portion 10 mm in length. The basal width of this ridge - like thickenin g is 6 mm, being 4 mm at top. It extends above the up pe r border of the elemen t an d forms a rod-like upper process gently curved inward. The .poster ior supragnath al attains a maximum height of 25 mm within the ridge-like thick ening. Laterally, the anterior th ickened por ti on, 20 mm in length, forms a protrusi on limited by the ver ti cal pos terior marg in. This protrusion corresp onds with the latera l 'pos terior supragna thal process occu r r ing in genus Coccost eus and oth ers.
Above this process, on the upper border on the element, is an impression to fit the ligaments or muscles. The lower margin, seen fr om the side, .has the outline of a fla t tened letter "W" , showing two sharp bends.
In agreement with this arr angem en t; the sur f ace tou ch in g the in f ragn a- tha] and occu r r ingon the mesi al side of this element is narrow .and
UPPER DEVONIANFISHES 301
arch ed posteriorly,while anterior lyit widens out overlapping the vertical ridge - like thickening and then ab rup tly narrow ing again.
Occurrence.- The Frasnian, horizon II in the Wietrznia Hill.
Genus Dinichthys Newberry, 1885
Remarks. - Genus Dinichthy s was erected by Ne wberry to include sp ecies D. herzeri described by him. Dater, a num ber of sp ecies was in clud ed into the genus, 'Some of which su bse q uen t ly were referred to ot her genera, while many of the remaining forms are known only on very inade q u a te fragmen ts.
In 1946, Dunkle and Bungart differentiated two groups of for ms in the dinichthyids. One of them, in those authors' opinion comprising D.
herzeri Newberryandgenus Gorgonich thys,is characterizedby jaws with a Iblunt crushing edge, while the other group, typ ically represented by D. terrelli Newberry and D. inter m ed ius Newberry, displays sharp, cutting edges. These sugg es ti ons led Lehman (1956) to sep arate D. herzeri from the remain ing forms, retainiog for it: the gen eric name of Dinich- thys and crea ting the new genus Dunkl eost eu s to include the forms of the '"ter relli" group.
Even such forms whose refer ability to gen us Dinichthys had not been quest ione d un til a shor t time ago, represen t various evolutionar y stages and lin es of this stock.To give a true!pictJure of the relations h ip of these for ms it will, doubtl ess, be necessar y to sepa ra te a number of su bge nera, or maybe, even genera. At tJhe present mom en t, however, Lehman 's other wise reasonable standpoint creates many practical difficulties. It eith er lead s t'oa mechanical assignment of all forms, D. herzeri excepted. to the newgenu s Dunkleosteu s, eng en der ing thepossibihty of bh eir being sub sequen tly shi fted from one to an otlher sys te matic un it, or left un- classifie d. Both these possibilities seem obvious ly un recomme ndable to the pr esent author Who is prompted tentatively to retain th e old systematic arramgernen t of Dinichthys alterab le in the future, after a detailed revision 'based on stud y of new materi-al concerning t'he now in ad equat ely known forms .
Dinich thy s pu.>tu !osu s Eas bmam, 1897
(text-fi g . 8, 9; pl. IV, V; pl. VI, fig. 1-3)
1897. Di nichthys pustulosu s Eastman ; C. R. Eastmen , On the relations..., p. 38.
1898. Dinichthys pustulosus Eastman ; C. R. Eastman, Some new points..., p. 748-- 754, fig. 1, 2.
1907a .Di ni ch t h y s pustulosus Eastman; C. R. Eastman , Dev on ic fishes..., p. 130-13Q.
pl. 12.
1918. Dinichthy spus tulosu s Eas tma n ; L. Hu ssa k off & W.L. Brya n t , Catalog of fo s- sil fishes..., p. 50-53, pl. 12; pl. 13, fig . 1, 2, 4.
J!l5fi. Dinichthy s cf. pustulosus Kulczyck i; J. Kulczycki, On the parasphe noid..:.
p.105----106, pl. 1, fig. G;pl. 2, fig . 3.
302 JULIAN KULCZYCKl
Material. - Material consisting of two large cranial fragments, one [rom the Lower, the other from th e Middle Frasnian in the Wietrznia hill; fragments of the median do rs al , nuchal, paran u ch al and anterior lateral plates from the Middle Frasnian of Wietrznia, while an anterior sup r agn athal has been recovered fr om the lower Cheiloceras beds, and two median dorsal fragments from the Frasnian hori zon III (Man tico- cera s beds) in Kadzielnia.
Description. - Head shield fragment from the Low er Frasnian of the Wietrznia hill (fig. 8B; pI. IV) comprises a complete nuchal and right pa- ranuchal, part of left paranuchal, both centrals without anterior processes, medial part of the marginal and a small portion of the postorbital. This sp ecim en has not been distorted and exhibits the natural doming of this portion of the head shield.
On the posterior margin, limited by the nuchal, the head shield is with a roof-like bend of about 130°. Farther to the front the doming grows gentle, more arcuate an d, beginning from the anterior suture of the nuchal hone, a shallow , ex tensive depression is indicat ed . stretching to the sides of the supraorbital lines on the centrals.
The nuchal is with a mark edl y regular outline which is almos t perfectly symm etr ica l. Its free outer sur f ace is of tr ap ezo idal form, 110 mm in height and wi th the basal width eq ual to about 180 mm, whe n measured along the cho rd line between the mos t outlying late r al poin ts.The posterior margin, limiting the nuchal gap, is sligh tly concave . ar ched, prov ided with a centra'l ipr oc ess, 40 mm broad at the base. The anterior margi n, 68 mrn lon g , Iimiting bo th cen trals, runs in a straight line across the head sh ield, interrupted by only three sm all, sharp pro- cesse s. The midd le one of these wedges in bet w een the two cen tral s.
while the two others are placed on the side en ds of the anterior nuchal margin '.'lith their apexes directed to th e middle of the respec t ive centrals. The lateral nuchal margins frontally uniting with the posterior central processes and to the hind with the paranuchals, show a gently arcuate cou rse, on ly slightly br ok en up in the area of contact with the sutur e be tw een the cen t ral and the paranuchal, In the hind most section only, th e suture between the nuchal and paranucha! for ms two larg er inden tations. Ventrally , the nuchal is consid erably narrower. Its posterior margin is 120 mm long. To the front the nuchal con t rac ts centrally to 45 mm broad ening out again to 55 mrn in the region of the anterior paranuchal margins. From this point the nuchal margins extend in conver ging rectilinear lines directed to the front, producing an angle of 70°.and wedging in between both centrals. In the centre of this area an elevation rises from which stretches a faintly indicated. ridge laterally limited by likewise slight grooves. At a distance of approx. 80 mm
UPPER DEVONIAN FISHES 303
from the anterior end there occu rs on the ventr al surfa ce of the nu chal plate a depress ion (the "doub le sockets" of Heint z), sharp ly limit ed at th e front as wen as at the back , 40 mm broad and 15 mm long and high . The bi-partition of the depression is in d ica te d by a slight notch on the front wall toget h er with. a small median crest, and two, similarly small :'cr ests on the back wall. The posterior limit of the dep r ession consists of a transve rsal ridge (" t r a nsversal com m issu re" of Heintz), considerably more massi ve than in Dini chthys inter m edius with a th ick ness of 20 mm.
From its back wall, a small median crest probably en ding in a larger process , as well as tw o lower lateralcrests ex t en d on the 'cen tral proc ess of the posterior nuchal margin. At the transversel commissu r e thenuchal thicknes s attains 30 mm. As ma y be seen in th e se cti on ob ta ined by the breaking off of the ar ea oc cupied by th e left joint socket, the nuchal wedges in this area int o the deep pocket produced by the mes ial para- nuchal margin and formsthemajorbulk ofthe ridge (the"hindthickening"
of Heintz) Which mesially Iimits theposterior lateradcranial cavi ties.
The paranuchal has the outline of a triangl e with truncated corners. The hind corner in vol v es the joint socket. The shape of the latter ele- men t suggests that the 'co n dyle must hav e been th ick and relatively short , The wid th of the joint su r fa ce measure d pa r al lel to the axis of th e joint is 22 mm, while the diameter of the cu r vatu re is 16 mm on the la teral margin and 14 mm on the mesia l . It shou ld be stresse d tha t the axis of the joint is no t pla ced hori zontall y , as figured by Heintz in the re- con struction of the skull of Dini ch th ys intermedius (1932, fig. 35), but runs obliquely from outs ide of the top and front mesially downward and backwa r d at an ang le of approx. 15° to the horizontal line drawn across the head shield. The lower lip of th e join t socket unites with the base of the joint process (lacking in the specim en under consideration): At th e base it is 14 mm wide an d 6 mm thi ck. Quite close to the boundary between the outer margin of the joint surface and the mesial margin of the joint process, th e paranuch al margin produces a moderately conspicuous, sharp process tr a v ersed by the groove of the lateral line passing on to the anterior dorsolateral. At a small distance from this place , th e posterior la t era l margin of the paranuchal limiting the d eft between the head shield and body armor ben ea th the joint, forms a small list wh ich, wi th head low ered, is over'lapped vby iJhe front marg in of th e pecto ral gird le . Mesially, the upper Up of the joint surface form s ashamp, beak-like proces s overhanging the joint cavity and at the same time closing UJP the pocket-like depression of the median paranuchal margin occupied by the la t er al part of the nuchal- plate. From this point, along the lateral part of the posterior nuchal margin, extends the fair ly long shelf-like list, taking part in the limitation of tJhe anterior head shield
304 JULIAN KULCZYCKI
mar gin. This process rese mb les a sim ila r structu re dn Plourtiosteus traut- sch oldi. The anter io r paranuchal margin con tactin g with !!he central and marg inal plates is irregularly arcua te . The outer par anu chal surface is traversed by th e sensory lime can al, by Gross 'referred to as tempor al, while Heintzcalls it margin al , an d by an "occipital ca n al" (called so in the nomenclature of Gross, by Sten sio called the "poste r ior pit-line") not
Fig. 8. - Dinich t h y s pustulosus, part reconstr uction of head sh ield (dotte d areas): A from the Middle Frasnian , B from the Lower Frasnian of Wietr zn ia ; C centra l.
N nuchal , M marginal, PN par an uch al, PrO preorbital, pta postorbital.
UPPER DEVONIAN FISHES 305
reaching the suture with the central , In the angle produced at t'he contact of these canals is the opening of the en d olyrnp h at ic canal. At a distance of 10 mm from the 8IPex of this angle , the tempor al canal branches off passing onto the anterior dorsol ateral . The ventral surface of the nuchal in Dinichthys pustulosus is distinguished by the consider - able width of the mesial step-like ele vation forming a pocket for th e la ter al nu chal margin an d, tog ether with it, prod ucing the hind thick- en ing of Heintz. This th ickening as compared to that in D. interm ediu s, is very massi ve and characterized by considerable wid t h , increasin g an t er ior ly (4~ mm above the joint socke t, 57 mm ne ar the transversal th ick en ing, limiting the nuchal depressi on). Within the cen tral portion of the hind thickening, along its lateral side, a broad but sh allow depression extends ventrally, wh ich, to the hind passes into a similarly wide and low blind canal, rapidly growing narrower. Within the lateral wall of th e hind head shield thickening, formed by the vertical paran uchal shelf, runs the endolymphatic canal. Its inner opening is placed at the an ter ior end of the above mentioned thi ckenin g oppos ite to the poin t of convergence of the nuchal, paranuchal and central su tures.
The centrals show an intricate ou t line. Medially they are united by som ewh at flexuous suture. In th e hind of the mes ial part they are trans- versally truncated by the nuchal element st re tch in g far to the front. The posterior tongue-shaped processes of the centrals adjoin the fore part of the lateral nuchal margin, Laterally to th ese proces ses wedged in betw een the nu ch al and P aranuch al, the margin of th e central after a slight bend resume s its rectilinear course sidewar d to touch the genal plate where it curves and then mes ially runs on arcua tely forward . The wid th of the centr al is 92 mm a'S measured from the poin t wh er e the two centr als and nuc hal come together to the point of converg ence between the cen tr al, genal and paranuchal. The length is 97 mm, as measured from the hin dmos t point of the posterior process laterall y to the frontal margin of the an terior pr ocesses which are missing on the here cons id ered specimen. On the external surface of the cen tral pla te, su p r aor bit al and central , sensory line canals are visible, converging to the middle of the element. The lat t er of these lin es projects somewhat far ther across th e [pla te inwar d in relation to the sup raorbital line . Besides these two canals, an isola te d section of the sensory line (the
"Restkanal" of Gross,the "central pit-line " of Stensio) is also foun d on the central. After running inwards in a tr ansversal xldrection to the mid dle of tlhe element, this line bends backwards without, however, at t ain in g the margin ad jacent to th e nuchal. A considerable portion of th e ventral surface of th e central is overlapped by the plates encircling it so that its free surface is confined to the middle area. In the studied
Acta Palaeontologlca Polonlca - Vol. IIj4
306 JUL IA N KULC ZY CKI
specimen th is is 71 mrn in wid th and 74 rnm in length. This area is occ upied by a shallo w, bow l- lik e depress io n , withou t sh arp lateral limits, elsewhere surrounded by a semicircular thickening. At rth e boundary with the nu chal plate there is a groove . It forms an embaymen t near the end of the paranuchalat the opening of the endolyrnphatic canal.
Far ther th is embayment opens into the posterior lateral cavi ty and extends avera short distance along the su t u r e betw een the central and th e .p aran uch al.
The only preserved part of the marginal is that occupying a mesial position in rel a ti on to the la ter al line groove running across this element.
Along the anterior par-t of this Iin e, on the ven tr al surface of the plate, st retches a ridge- like thickening which posteriorly low ers down an d becomes sharp-e dged. It cons titutes the hind part of the "la te ral consolidated par t" of Hein t z. At the bound a ry be tw een the ma r g inal and the postorbital lit is 30 mm lon g .
A large area of the external surface is smoothed ou.t, undam ag ed tuber cu la tion is to be found on the centrals orrly. The tuber cles are very minute , below 0.3 mm and densely dispose d (100 to 200 over 1 em").
The parasphenoid , alre ad y described in deta ils by the pr esent au thor (Kulczyek i, 1956) was found together with the abov e con sidered head sh ie ld fragment. From the same elemen t in Dini ch thys terre lli it diff ers primarily in the pr esence on the dorsal su r fa ce of a small tu be r cu lat ed area. The other differences main ly concern pr op ortions .
The other cranial fragmen t (fi g. SA; pI. VI, fig. 2) from the Mi d dle Fras n ian beds of the Wietrznia hill (hor izon II), bel on gs to an individual wit h simil ar, perhaps somew hat lesser dime nsions, an d is characterizedby less regular shape of bon es. This is particu larly so in the case of su tu re betw een the two centrals which displ ays a marke d ly flexuous cour se , also in that bet we en the centrals and the nuc hal which is eq ually zigzag an d less sym met r ical than in the above described spe cimen. The proper- tions of the respective bones are also somewhat different. For example, the nu ch al is here 'r ela tiv ely short and wide, being 90 mm lon g as measured dorsall y adong the med ia n line, wh ile the wid th of the anterior margin is 75 rom, the length of the posterior marg in bei ng pr ob ably about 180 rnm. The rather bad state of preser vation of the stud ie d speci men mak es imposs ib le a closer comparison of proportions in the par ti cu lar pla te s, it would seem, howe ver, that the sho r tnessof the nuchal is its chief characteristic . The ventral len g th of the nu chal is 100 mm as against 130 mm displa y ed by the lower Frasnian specimen , The dist an ce from the bas e of the join t process to the anter ior nu ch al extremity is here 155 rnm,being 175 mm in the Lower Frasnian specimen. Corespond-
~ngly, the dist ance from th e point of divergence of the senso ry line on
I ,
UPPERDEVONIAN FIS H ES 307
.the marginal from the median head line , measured .on the cranial . cu rva tu r e, is 140 and 130 mm respectively, The proportions oftJhe cen trals were markedly similar or even the same as obs erved in the
.indiv id u a l fr om th e Lower Frasnian. The width and leng th (w ithou t the
anterio r process) ar e, 1n botJh leases, 70 mm. The length of the an terior
'process is not less than 30 mm.
The considered specimen is with an almost perfectly pr eserv ed marginal. It is a relatively narrow bon e, with wid th never exc eeding 50 mm and length up to 110 mrn, forming the latera l marg in of the craruial dome with the poster ior later al cormer. The la tter pr ojects far to th e side (the dista nce from its apex to th e median head line, measured on the curvature , belingajplprox . 200 mrn) and does not display the presence of an independen t rpostmar ginal element . The lateral border of the marginal is in curv ed to produce an angle at the middle bone level.
Its shape indica tes that , similarly as in Coccosteus and other species of Dinichthys, the union of tJhe crandal dome wdth the bones in the cheek area was not intimate. Th e boundary with the postorbital is an teriorl y in d en t ed where th e sensory lin e groove passes from one bone to the
'next. This is similar to what has been observed lin the before des ordbed
specim en and in the fragment of a North American head shield (E as t m an, 1898, fig . 2). On the lower sur face, from the apex of the process formin g the exterior angle of the skull to the middle of the elem en t and then parallel to the sensory line, stretches a thickening. It tis low at dts beginning, but gains in height as it advan ces; sharp- edged in its hind part, and [particularly so in bhe centralrr egion. This lis the pos te r ior par t of the so called lateral consolidated part. It displays a frontal heigh!
of 25 mm. This thickening passes on t'o the postorbi t al 'where, about the midd le of th e element it tapers into a rather narrow crest, inwardly inclin ed . On tJhe ventral slide it exhibits a concavity (the double sockets) posteriorly steepl y limited.
The middle part of the pos torbital being damaged, it is im pos sib le to ascertain whether the median cranial process ex ist ed at all and how it was shaped. Hereabout, along the course of the 'cen tral groove on the ex t ernal surface , th e trdangula r, shelf-like \proc ess of the central plate is wedged into the inner border of the mar gimal. On the ventral surface, th e suture between the marginal and the postorbital has a similar cours e as tha t in Dinichthys inte rm ediu s.
The course of the sensory 'line grooves displays some individu al va r iations as compared with the Lower Frasnian head sh ield . To say, th e coo tral groove does not on the inward side gobeyoll'd the line in d ica ted by thecourse of the supraorbital groove.The so called vestigial gro ov e or the median 'Pit-line lies very close to 't!he central groove, cur-
308 JU LI AN KULCZYCKI
ving backward it reach es the margrn of the central plate contac ting with the nuchal. In these det a ils the here describ ed specimen closely resembles the head shie ld described fr om North America (fig. 9).
In addition to these major samples, two smaller cranial fragments have been found dn the Middle Frasn ian of the Wie trzn ia hill.
An incomplete nuchal represents an individual at 'least three and a half times larger than that from the Lower Frasnian. On tJhe ventral side it exhibits a concavity (the double sockets) posteriorly steeply limi- ted . On 1lhe posterior margin there .is a surface for the process of the paranuchal reachmg far in w ar ds. A deep notch in 1lhe frontal part of the lateral margin indicates that the paranuchal overlapping the nuchal, particularly so on tJhe dorsal side, was itself wedged into the margin of that element by means of a stout sh elf .
A fr agmen t of the joint socke t area of the paranuchal is, on the contrary, to be referred to a considerably'smaller individual. The width of the joint socket, measured parallel to 1:Jhe axis of the joint, is scarcely 13 rnm, while the diameter of the curvature is 9 to 10 mm. In spite of the sma-ller dimensions of that specimen the size of the ornaanenting tubercles and its density do not diff er from those common in larger individuals, which indicates that the size of tubercles did not alter with the age of the individual.
Of the jaw apparatus belonging to the here studied form our mater ia l only contains the r ight ra n ter-ior supragnathal coll ected from the lowe r Cheiloceras beds of Kadzielnia (p], VI, fig 1). Its shape is that typical of genus Dinichthys. We may distinguish here an anterior part which is narrower, being only about 15 mm wide , and a wider posterior (later al) on e, abou t 30 mm in width. Both th ese parts meet at an angle of nearly 90° forming a ridge, i.n the lower portion made conspicu ous as a rounded crest. In the upper ,pa,rt it iis replaced by a tr iangular nearly plane sur f ace. Along this rid ge the anter ior supragn ath al is thickened and el ong a ting downwards forms a tooth-like proc ess , trian g ular in section.
Another tooth-like process , though much small er, occur s at the lower end of the posterior ed ge of the element. The upper end ad' th e anterior par t continues as a lobe-like process, curved inward. The presence of a series of "denticles" on the vertical edge of the tooth-like process is an ind ex rch arac ter permit ting the assignmen t of th is jaw element to the remains of Dinichth y s pustulosus. The height of the preserved par t of the anterior supragnathal is 42 mm. Another 10 mm must be added to th is figure to make up the missing apical pick of the tooth-like process.
Of the bod y armour the Holy Cross .Mts, mat erial contains fOUT fragments of the median dorsal and on e orfthe anterior lateral.
The .most comple te specimen of .the median dors al (pl. V) has been
