Trinocladus divnae and Montiella filipovici – a new species ( Dasycladales , green algae ) from the Upper Cretaceous of the Mountain Pa { trik ( Mirdita Zone )

Two new dasycladalean species from the Upper Cretaceous of the Mountain Pa{trik, Kukes Cretaceous Unit of the Mirdita Zone are described: Trinocladus divnae sp. nov. is characterized by variable size of the thallus, relatively narrow main axis, typical Trinocladus organization of the laterals and thin calcification limited to the distal part of the thallus which includes a swollen part of secondaries and short tertiaries. Often, the internal portion of the whorls (except sometimes the main stem membrane), tends to dissolve and form dissolution cavities filled with cement. Montiella filipovici sp. nov. is characterized by a primary skeleton made of a thin individual sheath around a fertile ampullae, often obliterated by recrystallization. Four to six laterals, each giving one secondary and one fertile ampulla located on the upper side of the relatively thick short primary lateral. Upper Cenomanian limestone with Cisalveolina fraasi and Trinocladus divnae sp. nov. was deposited immediately before the events that resulted in sea level rising. The middle and upper Cenomanian eustatic-tectonic processes had different effects in the Pa{trik shallow water areas, depending on the distance from the basinal part of the Unit. Bathymetric changes in a part of the Pa{trik sedimentary area were not significant, even negligible. Montiella filipovici is found in the post-fraasi shallow water sequence, assigned to the ?uppermost Cenomanian–lowermost Turonian (= Whiteinella archaeocretacea Zone p. p.; a short stratigraphic gap, in a part of the area, is noted). Shallow water limestone with Turonian taxa, corresponding to the helvetca Zone, occurs a few meters upward. Supplementary note: the species Cylindroporella parva RADOI^I] is transferred in the genus Montiella, the species Permocalculus elliotti JOHNSON is transferred in the genus Trinocladus, while the species Trinocladus bellus YU JING is transferred in the genus Belzungia.


Introduction
The Cretaceous succession of the Mountain Pa{trik is an attached platform (superimposed paleogeography) overlaying the Diabase Chert Formation, serpentinite and Tithonian-Berriasian carbonate clastics (flysch auct.) in the north.From the middle Cenomanian into the Turonian, it was a ramp -a transitional stage from the platform to the basin.

Systematics
Order Dasycladales PACHER, 1931Family Triploporellaceae (PIA, 1920) emend.BER-GER & KAEVER, 1992 Subtribe Triploporellinae (PIA, 1920) emend.ASSO-ULLET et al., 1979 Genus Trinocladus RAINERI, 1922 According to ELLIOTT (1972, p. 619), the tubular thallus of Trinocladus is composed of "Successive verticils of radial branches, each branch showing outwardly widening primaries giving rise to several secondaries, and these in turn to bunches of tertiaries.Branches of the lower verticils may not show the full detail.Branches usually not alternate in position from verticil to verticil." Based only on a transversal section, RAINERI (1922) maintained that a trichotomic partitition of the laterals is characteristic of the genus.In fact, the main generic feature is the form of laterals: club-shaped phloiophorous primaries with a more or less large subspheric distal part, similar shaped thinner secondaries, four or more per each primary, and bunches of similar short tertiaries.
It should be mentioned that, in some cases, recrystallized or poorly preserved Trinocladus tubes were also ascribed to Permocalculus or to Griphoporella.
Specimens of such preservation are often really difficult to distinguish from some Permocalculus.Compare: fragments of T. divnae in Pl. 3,Figs. 10,11,with "typical Permocalculus debris" illustrated by JOHNSON (1969, pl. 17) and by JOHNSON in JOHNSON & KASKA (1965, pl. 14).In the same paper, JOHNSON introduced a new species Permocalculus elliotti, which is, in fact, Trinocladus (see further text).
This section shows the thinly calcified central stem membrane with well preserved insertion points of 4 laterals.The central stem, the irregular space around it and between the laterals were early post mortem filled with matrix.Open pores on the calcareous tube surface (dentate surface) is the evidence of the tertiaries.Primary and secondary laterals are not preserved predominantly due to dissolution in the post-filling phase with matrix.The two primaries are not completely obliterated by recrystalization (arrows).Dissolution cavities were subsequently filled with cement.This space, corresponding to the space of the laterals R1-R3 has an inverted triangular form (Fig. 2, arrows).
The Albian-Cenomanian succession of the Bistrica lies on Upper Triassic limestone (= large block sliding, during the Cimmerian event in the Diabase Chert For-mation) and on the Diabase Chert Formation (RADOI-^I], 1994).
Diagnosis.Thallus cylindrical, central stem narrow with whorls consisting of three orders of similarly shaped phloiophorous laterals; 7-8 primary laterals bear probably six relatively long secondaries, giving rise to bunches of fine short tertiaries.Distal widening of the laterals relatively small, maximum of 0,076 mm in the primaries, about 0,050 mm in the secondaries and about 0.025 mm in the tertiaries.Length of the primary lateral is almost equal to both secondary and tertiary laterals.Primary calcification delicate, prevailing around the distal portion of the thallus.
Main stem diameter (given on a few sections only) 0.126-0.177.
Length of primary laterals (= pores) nearly half the wall thickness.
Sometimes, the contour of the main stem is also recognizable (Pl.1,Figs. 5,9;Pl. 3,Figs. 2,4), or, even, the calcified stem membrane is preserved as a thin black line (Pl. 1, Fig. 7).The central stem and proximal whorl area, in a few individuals, occur as a cavity with the internal wall surface more or less zig-zag undulated (Pl. 1, Figs. 6, 9, 10).The internal structure of the specimen shown in Pl. 1, Fig. 9 seems, at a first glance, relatively well preserved.The structure of the whorls, in this case, is obliterated: only contours of the recrystallized whorl areas and the intervening space can be distinguished.
Here, subcircular sections give a wrong impression that they are sections through thick laterals.Most likely, the membrane of the primary and secondary laterals are not at all or only slightly calcified.They were enveloped in a thick mucilage layer giving a cuplike form to every unit of laterals (triangular in the sections), which are, in this case, completely recrystallized.
Individuals with a calcified distal thallus area, around the swelling of secondaries and of dense short tertiaries, are presented as thin-walled cylindrical calcareous tubes, relatively resistant to dissolution and abrasion (Pl.2, Figs.1-5).The small sized fragments of this thin fineporous calcified wall is difficult to recognize as dasycladalean skeleton elements (Pl. 3,Figs. 10,11).
Comparing these differently preserved specimens, I could not immediately decide: whether they were the same species.Specimens with a thin distal calcification are ascribed to Trinocladus divnae because of the somewhat larger size of the thallus and, especially, the difference in the preservation are not of specific maximal values.Smaller individuals generally had an earlyaltered internal structure (recrystallized) and were more resistant to break.The thin calcareous wall of larger specimens, although resistant to dissolution and abrasion, were more friable.
Relations.This species resembles Trinocladus tripolitanus RAINERI the most, which has the same number of primary laterals but is not so variable in the size of the thallus.The main difference lies in the distal part of the thallus: relatively delicate secondaries of Trinocladus divnae bear dense bunches of fine tertiaries, forming a resistant thin calcified wall.
Type species is Montiella munieri, from the Montian of Belgium.Other species of the genus, Montiella ma-cropora, was contemporary described from the Thanetian of the Paris Basin.Isolated specimens and fragments of the both species were studied by GÉNOT (1978, 1987, in: DELOFFRE & GÉNOT, 1982).This author (1982, p. 108) compares the calcareous sleeve of both species with those in some Neomeris "chés lesquelles les ramifications primaries et l'extrémité proximale des ramifications secondaires ne sont jamais conservées." The find of genus Montiella in the Cretaceous sediments is of a later datum: when Cylindroporella elitzae BAKALOVA and Cylindroporella benizarensis FOURCADE et al. were transferred to the genus Montiella (RADO-I^I], 1980, GRANIER, 1990).The difference in the extent of calcification of the Paleocene and Cretaceous Montiellae is readily evident.In contrast to the Paleocene species, the known Cretaceous species have a calcareous sheath around the proximal part of the whorl with, in the some specimens, a well preserved morphology of the central stem.
In the calcareous sheath of the known Cretaceous Montiellae, as a rule, the pore of the secondary is not differentiated from the pore of the primary lateral (secondary effect).They look like a single pore: a thick and short proximal part with a fertile ampulla followed by somewhat narrower tube, distally enlarged having the protective function of the ampulla.
Besides the fertile ampullae, other whorl elements are often not or only partially preserved.Therefore, it is often difficult to distinguish the calcareous sleeves of Montiella from those of Cylindroporella.Bearing in mind that the type species of the genus Cylindroporella is poorly preserved (some structural elements are obliterated), the question is: what is Cylindroporella?The Cylindroporella problem is discussed by BARATTOLO and PARENTE (2000).sp. nov. Pl. 4,Pl. 5,Pl. 6, Origin of name.The species is dedicated to my friend and colleague Dr. Ivan Filipovi} (Belgrade), for his contribution to the study of on the Paleozoic in Western Serbia.
Further upwards (the bedding is not well visible), the lower Turonian (equivalent to the helvetica Zone) is documented by Moncharmontia apenninica (DE CASTRO), Pseudocyclammina sphaeroidea GENDROT (sample 015119), and the rudists Hippurites, Durania, Biradiolites and Distefanella.The interval between the Cisalveolina fraasi Zone and the lower Turonian is equivalent or partly equivalent to the Whiteinella archaeocretacea Zone In the Gradi{te succession (the same Cretaceous Unit, Fig. 1), Halimeda elliotti occurs abundandly in some beds of the Hemipelagic Sequence (= Whitinella archaeocretacea and Helvetotruncana helvetica zones).In the Metohija Cretaceous Unit, the abundance of Halimeda elliotti associated with Helvetotruncana helvetica is known from the Zabel Section (RADOI^I], 1993, 1998).
Diagnosis.Thallus with a narrow central stem and whorls commonly consisting of 6 laterals, exceptionally 4 or 5.Primary laterals arranged in quincunxes, short and relatively thick, each bears a fertile ampulla and a secondary lateral.Egg shaped slightly inclined upward fertile ampulla located on the upper side of the primary lateral close to the central stem, a secondary lateral grows from its distal end.Ampulla pedunculus is short, usually not clearly differentiated.
Walls of the fertile ampullae have been individually calcified.This primary calcareous skeleton is altered or partly altered.
Dimensions (in mm) (extreme value in brackets): External diameter 0.607-0.708(0.759); the transverse section with 5 laterals in the whorl shown in Pl. 5, Fig. 5 is a specimen with a narrower thallus diameter -0.430 mm.
Length of the ampulla with pedunculus 0.180.Length of the primary laterals up to 0.127.Diameter of the fertile ampulla up to 0.170.Diameter of the primary lateral about 0.051.Description.The surface of the calcareous tubes was more or less eroded, often to half of the fertile ampullae (Pl.4, Fig. 9).The fertile ampullae primary have been individually calcified as more or less thin carbonate envelopes (about 0.002 mm).A similar primary calcification is not observed in the laterals, they were poorly preserved, probably due to weak or no calcification at all.The form of their distal-cortical part is not known (it seems they were much enlarged).The best example of individual calcified fertile ampullae is the transverse section in Pl. 2, Fig. 5.Some other sections, with a preserved individual sheath around the ampullae, and primary contact between them are illustrated in the same plate.In the same calcareous tube, parts of the skeleton may be differently preserved.An example of the different grade of the obliterated structure in the same whorl is the transversal section in Pl. 2, Fig. 4: well preserved, slight contact between the ampullae observable as a black line, and both, the sheath and the space between the ampullae are almost obliterated by advanced recrystallization in the other part of the section.The mentioned transverse section with 5 laterals is also an example of gradual alteration.The original sheath around the ampullae is preserved in part of this section, and obliterated by recrystallization in the other part.
Relations.Montiella elitzae and the very similar Montiella benizarensis are species with a larger thallus bearing 6-8 laterals per whorl and more variable dimensions than M. filipovici characterized by slightly variable thallus dimensions.
Some specimens of Cylindroporella elitzae and Cylindroporella benizarensis (are these two species?) are a nice examples of a post-mortem process resulting in axis widening at the whorl level (RADOI^I] et al., 2005, pl 1, fig. 3).The primary calcification around the fertile ampullae in these species is not preserved, except the thin calcification around fertile ampulla of Montiella elitzae from Eastern Serbia (RADOI^I], 1980, pl. 2, fig.4), which indicates the same primary calcification as that of Montiella filipovici.Turonian, Tripolitania, Libya, The taxon is found in the type level of Montiella filipovici and also in association with Trinocladus divnae (Pl.6, Figs.5-7).The subaxial section, Fig. 7, is the only specimen of this species with preserved pores of primary laterals upward bearing the fertile ampulla (the structure of the genus Montiella).The secondary laterals most probably were not calcified.

A list of algal flora in the Cretaceous of Pa{trik
From the Turonian of Sinai in Egypt, the species was presented by IMAM (1996, 1b, not 1a).A primary calcification of this specimen, the individual sheaths enclosing the fertile ampullae which is the feature of the genus Montiella, is well preserved in the part of this recrystallized body.(JOHNSON, 1965)  Although the calcareous sheath of the illustrated specimens is diagenetically altered, sections in figures 1-3 give sufficient data on the dasycladalean nature of this species.Branching arrangement -primary, secondary (Figs. 2, 3, on left) and tertiary (Fig. 3) laterals is of the Trinocladus pattern.Accordingly, the species is transferred into the genus Trinocladus RAINERI, 1922.In order to obtain a diagnosis, a study of the type material is necessary.(YU JING, 1976) comb. nov. Trinocladus bellus. spec. nov., YU JING, 1978: pl. 8, figs.10 (thin slide 28434) and 11 (thin slide 28435), ?Fig. 9, non Fig. 12, Paleocene-Ypresian of Lungma Region, China

Belzungia bella
The holotype of Trinocladus bellus is a large fragment of the calcareous tube -longitudinal-oblique section through 6 or 7 whorls.The insertion points of the primary laterals in this section are not preserved because the main stem is secondary enlarged.Thick short primaries, thick irregular secondaries and somewhat thinner tertiaries, give rise to further laterals, thin and anarchically arranged.Whorls bearing such arrangement of laterals characterize the genus Belzungia, MORELLET, 1908.The new combination refers to two out of four sections illustrated by YU JING (1978, fig.10), holotype and transversal section in Fig. 12.This species, introduced on insufficient material, is different from other Belzungia species by coarser proximal (3 orders) and seemingly somewhat more anarchically arranged distal laterals.

Fig. 2 .
Fig.2.Trinocladus divnae sp.nov.Holotype, slightly oblique section; thin slide RR2379, × 61,5.Notice the insertion points of 4 laterals.Arrows: recrystallized space of inverted triangular forms corresponding to units of laterals (R1-R3), and on the bellow the two pores of primaries which are not completely obliterated by recrystalization.