In North America the base of the Capnodoce Zone of Blome (1984) is found in the ? upper Camian with the Justium novum Subzone forming the oldest part of this Zone (Textfig. 6.3). The base of the Capnodoce Zone is defined by the first occurrence of
the genus Capnodoce, and the oldest positively datable samples from this study contain members of the genus Capnodoce (C. anapetes, C. sp. aff. C. copiosa, C. insueta, C. kochi and C. fragilis) which commonly occur in the Upper Triassic (Camian-Norian) of North America. The Justium novum Subzone in North America contains Catoma, Justium, Canoptum, Pachus, Gorgansium, Renzium, and Betraccium, which are present in equivalent age samples from Indonesia, although at species level contents are markedly different and therefore it is possible that this subzone was not sampled or is absent in Timor. Given the structural complexity of the Aitutu Formation in West Timor it is quite possible that the assemblages of the Justium novum Subzone are present and were not sampled. The Xipha striata Subzone forms the middle part of the Capnodoce Zone and appears to contain a similar assemblage at species as well as generic level in both North America and Indonesia. Commonly occurring species found in both regions include: Capnuchosphaera deweveri, C. schenki, C. smithorum, Capnodoce insueta, Renzium adversum and Corum regium, however, Xipha striata and other members of the genus Xipha which occur in North America appear to be absent in Timor. The top of the Capnodoce Zone contains the Latium paucum Subzone. This subzone contains genera common to both North America and Timor, however, at species level the assemblages have little in common (only Pachus longinquus and Capnodoce fragilis are found in Indonesian and North American assemblages and these are not necessarily of the same age). Assemblages from Timor lack Latium and its representative species occurring at the top of the Capnodoce Zone of Blome (1984), although this may have been caused by sampling gaps rather than a true absence.
The Betraccium Zone in North America defined by Blome (1984) is an Oppel Zone covering the upper part of the middle Norian to the upper Norian (Upper Norian here includes the Rhaetian, although Carter (1993) illustrates true uppermost Triassic i.e. Rhaetian radiolarian assemblages which appear to differ from the upper Norian of Blome, 1984) and is divided into two subzones. The base is defined by the first appearance of the genus Betraccium and not the final appearance of the genus Capnodoce from the zone below as the base of the Betraccium Zone in eastern Oregon is missing. The oldest subzone is the Pantanellium silberlingi Subzone which was introduced by Pessagno (1979) and was emended by Blome (1984) and is characterised by the presence of Pantanellium silberlingi, various species of Sarla, Capnuchosphaera, and Pseudoheliodiscus. There appear to be no species characteristic of this subzone from North America in assemlages recovered from
Timor, again bringing into focus the question of true absence from Timor or sampling gaps. Genera making their final appearance in this subzone include Capnuchosphaera. The youngest part of the Betraccium Zone is the Betraccium deweveri Subzone which has a range of upper Norian and its base is defined as being above the final appearance of Capnuchosphaera. Assemblages from Timor contain examples of Betraccium deweveri, however, they do not contain many other species of Betraccium, Pantanellium, Ferresium or Laxtorum as seen in North America.
In the study of Carter (1993) (Textfig. 6.3) the Betraccium deweveri Zone is the oldest assemblage and is believed to show a more limited range than the Betraccium deweveri Subzone of Blome (1984) representing only the upper Norian. The range of the species Betraccium deweveri defines the zone as well as the following genera (all of which are common in the Rhaetian): Ferresium, Fontinella, Loupanus, Canutusl, Canoptum and Haliommal. Only Ferresium, Canutus, and Canoptum are present in the upper Norian and Rhaetian of Timor.
Assemblage 1 of Carter (1993) contains Archaeocenosphaera, Paronaella bifida, Pseudohagiastruml tasuense, Droltus orchardi, Squinabolellal trispinosa, and Livarella densiporata. In the Upper Triassic of Timor Paronaella sp. aff. P. bifida and Livarella densiporata are present.
Assemblages 2a and 2b of Carter (1993) contain Fontinella, Paronaella, Praeparvicingula, Entactinosphaeral, Ferresium, Kozurastrum beattiense, Pantanellium, Eptingium ?, Haeckelcyrtium and Squinabolella desrochersi, of which Kozurastrum beattiense and Squinabolella sp. aff. S. desrochersi are present in assemblages from Timor.
Assemblages 2c and 2d in Carter (1993) has no characteristic species in common with those recovered from Timor. Assemblage 3 and samples from Timor only have Globolaxtorum tozeri as characteristic species in common.
Distinctive changes in the faunal composition of the upper Norian and Rhaetian radiolarian assemblages take place in the Queen Charlotte Islands, Timor and elsewhere. These changes have relatively few species as common components, however, at generic level with a few notable absences both sets of assemblages appear ahke. A lack of greater sample coverage in Indonesia prohibits true testing of
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Carters assemblages. The following genera are present in the Queen Charlotte Islands but absent in Timor: Fontinella, Haliommal, Loupanus, Praeparvicingula, Eptingiuml, Risella and Praecitraduma. These absences may once again be either the result of true absence or sampling gaps. The affiliation of both sets of samples is borne out by distinctive changes in the genus Paronaella, the presence of Citraduma, commonly occurring Kozurastrum, Squinabollela, Livarella, Nassellaria gen. and sp. indet. B (of Carter) is very similar to Pseudolivarella barkhami n. gen. and n. sp. (this study), Deflandrecyrtium, Pseudohagiastrum and Tetraporobrachia. Further investigation and sampling may well give a more complete overview of the Rhaetian from Timor and increase the similarity between the radiolarians of both areas.