PBDB Collection

Little Rapid River 1 (Oligocene of Australia)

Where: Tasmania, Australia (41.2° S, 145.2° E: paleocoordinates 58.0° S, 144.3° E)

• coordinate stated in text

When: Proteacidites tuberculatus pollen zone, Early/Lower Oligocene (33.9 - 28.4 Ma)

• The fossil-bearing mudstone has been dated by palynological correlation by M. K. Macphail. He considers that the mudstone belongs to the lower Proteacidites tuberculatus Zone of Stover & Partridge, 1973 (hill & Bigwood, 1987).

•The mudstone lens has been dated as Late Oligocene based on pollen analysis (Hill, 1987).

•The sediments are dated palynologically as Early Oligocene (Macphail et al. 1994), in Guerin & Hill, 2003.

Environment/lithology: fluvial-lacustrine; poorly lithified, sandy mudstone

• It is likely that the Little Rapid River deposit represents a Tertiary lake which has undergone a dramatic change in depositional regimes. The lower unit is characteristic of a low energy environment such as the centre of a lake with low stream input. Organic laminations would be the result of fluctuating stream flow (possibly seasonal), the plant matter most probably being derived from vegetation lining inflowing creeks and streams or from the lake edge itself.

• The deposit is composed of two different lithological units, each corresponding with a separate environment of deposition. The upper sandy unit (approximately 50 cm thick) becomes lighter in colour higher up in the cutting, and eventually gives way to several metres of very pale-coloured sand with only fine particulate organic matter scattered through it. Both upper and lower units are consolidated when dry but become plastic when wet. Fossils from Hill, 1991 were extracted from mudstone lens.

Size class: macrofossils

Preservation: adpression

Collection methods: chemical, peroxide, sieve

• Fossils collected by R. S. Hill from 1992 to 1998 (Guerin & Hill, 2003).

Primary reference: R. S. Hill and A. J. Bigwood. 1987. Tertiary gymnosperms from Tasmania: Araucariaceae. Alcheringa 11(4):325-335 [C. Jaramillo/C. Jaramillo]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 166705: authorized by Carlos Jaramillo, entered by Andrés Cárdenas on 22.02.2015, edited by Carlos Jaramillo

Creative Commons license: CC BY (attribution)

Taxonomic list

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Angiospermae
Fagales - Nothofagaceae	Nothofagus glandularis n. sp.⁵, Nothofagus serrata n. sp.⁵, Nothofagus peduncularis n. sp.⁵, Nothofagus lobata n. sp.⁵, Nothofagus cooksoni n. sp.⁵, Nothofagus mucronata n. sp.⁵, Nothofagus tasmanica⁵, Nothofagus bulbosa n. sp.⁵ Nothofagus glandularis n. sp.⁵ Hill 1991 Nothofagus serrata n. sp.⁵ Hill 1991 Nothofagus peduncularis n. sp.⁵ Hill 1991 Nothofagus lobata n. sp.⁵ Hill 1991 Nothofagus cooksoni n. sp.⁵ Hill 1991 Nothofagus mucronata n. sp.⁵ Hill 1991 Nothofagus tasmanica⁵ Hill 1983 Nothofagus bulbosa n. sp.⁵ Hill 1991
Fagales - Casuarinaceae	Gymnostoma tasmanianum³ Gymnostoma tasmanianum³ Guerin and Hill 2003
Oxalidales - Cunoniaceae	Eucryphia sp.², Eucryphia aberensis², Callicoma serratifolia¹ Eucryphia sp.² Cavanilles 1798 Eucryphia aberensis² Hill 1991 Barnes & Jordan, 2000: specimens examined LRR1-4010, 4011, 4013-4014, 4016-4017, 4019-4020, 4022-4028, 4030-4045, 4047-4052, 4057. Callicoma serratifolia¹ Andrews 1809 Reference leaf specimen: LRR1-1648. Referred leaf specimens: LRR1-3000–-3003, 3005–-3009, 3013, 3016–-3020; reference infructescence specimen: LRR1-3015, specimens stored in the School of Plant Science, University of Tasmania.

Coniferales - Podocarpaceae	Dacrydium aciculare n. sp.⁸, Dacrydium tasmanicum n. sp.⁸, Lagarostrobos marginatus n. sp.⁸, Dacrycarpus linifolius n. sp.⁸, Dacrycarpus arcuatus n. sp.⁸, Dacrycarpus linearis⁸, Sigmaphyllum tasmanensis⁷ Dacrydium aciculare n. sp.⁸ Wells and Hill 1989 podocarp Dacrydium tasmanicum n. sp.⁸ Wells and Hill 1989 podocarp Lagarostrobos marginatus n. sp.⁸ Wells and Hill 1989 podocarp Dacrycarpus linifolius n. sp.⁸ Wells and Hill 1989 podocarp Dacrycarpus arcuatus n. sp.⁸ Wells and Hill 1989 podocarp Dacrycarpus linearis⁸ Wells and Hill 1989 podocarp Sigmaphyllum tasmanensis⁷ Hill and Scriven 1999 podocarp
Coniferales - Cupressaceae	Athrotaxis mesibovii⁶, "Athrotaxis rhomboidea" = Athrotaxis rhomboidea⁶, "Mesibovia rhomboidea" = Athrotaxis rhomboidea⁸ Athrotaxis mesibovii⁶ Hill et al. 1993 cypress "Athrotaxis rhomboidea" = Athrotaxis rhomboidea⁶ Hill et al. 1993 cypress comb. nov. Synonym: Mesibovia rhomboidea Wells & Hill, Aust. Syst. Bot. 2, 387-423 (1989). "Mesibovia rhomboidea" = Athrotaxis rhomboidea⁸ Hill et al. 1993 cypress
Pinopsida
Pinales - Taxodiaceae	Austrosequoia tasmanica n. sp.⁶ Austrosequoia tasmanica n. sp.⁶ Hill et al. 1993
Equisetopsida
Pinidae - Pinidae	Agathis tasmanica n. sp., Araucaria fimbriatus⁴ Agathis tasmanica n. sp. Hill and Bigwood 1987 Araucaria fimbriatus⁴ Hill 1990

¹Barnes and Hill 1999; ²Barnes and Jordan 2000; ³Guerin and Hill 2003; ⁴Hill 1990; ⁵Hill 1991; ⁶Hill et al. 1993; ⁷Hill and Scriven 1999; ⁸Wells and Hill 1989