Geology Reference
In-Depth Information
Misik, M., Sotak, J., Ziegler, V. (1999): Serpulid worms
Mer-
cierella
Fauvel,
Durandella
Dragastan and
Carpathiella
nov. gen., from the Jurassic, Cretaceous and Paleogene
of the Western Carpathians. - Geologica Carpathica,
50
,
305-332
Moore, R.C. (1962): Miscellanea (Conodonts, conoidal shells
of uncertain affinities, worms, trace fossils, problem-
atica). - Treatise on Invertebrate Paleontology, part W,
259 pp., Lawrence (Geological Society of America)
Railsback, L.B. (1993): Original mineralogy of Carbonifer-
ous worm tubes: evidence for changing marine chemis-
try and biomineralization. - Geology,
21
, 703-706
Schmidt, W.J. (1951): Die Unterscheidung der Röhren von
Scaphopoda, Vermetidae und Serpulidae mittels mikro-
skopischer Methoden. - Mikroskopie,
6
, 373-381
Ten Hove, H.A., Van Den Hurk, A.M. (1993): A review of
Recent and fossil serpulid 'reefs', actuopalaeontology and
the 'Upper Malm' serpulid limestones in NW Germany.
- Geol. Mijnbouw,
72
, 23-72
Weedon, M.J. (1994): Tube microstructure of Recent and
Jurassic serpulid polychaetes and the question of Paleo-
zoic 'spirorbids'. - Acta Palaeont. Polonica,
39
, 1-15.
Further reading
: K125
10.2.4.7 Crustacean Arthropods
Arthropods are characterized by segmentation, special-
ized appendices and a rigid exoskeleton that must be
shed or molted if the organisms change size or shape.
The skeletons of some arthropod groups also have a
good fossil record in carbonate rocks. Three of these
groups belong to the superclass Crustacea, a fourth and
most important group are the trilobites, regarded as an
extinct superclass (see Sect. 10.2.4.8).
Crustaceans recorded in limestones include ostra-
cods, cirripedians represented by balanids, and micro-
coprolites of decapod crabs.
Ostracods
Ostracods are bivalved mm- to cm-sized crustacean
arthropods, known since the Late Cambrian to occur
in nearly all types of aquatic environments. They are
valuable proxies for paleoenvironmental conditions
Plate 92 Serpulids and Other Worm Tubes
The plate displays calcareous worm tubes (-> 1-8) and worm tubes with walls consisting of agglutinated
grains (-> 9, 10).
1
Serpulids and coralline red algae.
Modern aragonitic serpulid tubes. Note distinct differences in tube diameter. Arrow
points to sessile foraminifera enclosed in crusts made by coralline red algae (black). Reef environment, Bermuda.
2
Temperate setting.
Serpulids occurring in modern beachrock, formed in temperate water. Serpulids are common constitu-
ents of temperate and cold-water carbonates. Note concentric shell structure (arrows). Black grains are volcaniclastics.
Fuerteventura, Canary Island, Spain.
3
Reefs.
Serpulids forming small-scale reefs in near-coast settings. Note fibrous cement rim around the annelid tubes. Late
Tertiary (Early Sarmatian, Miocene): Prut Valley, Romania.
4
Rock building.
Gregarious growth of serpulids in brackish-water environments may result in the formation of serpulid
boundstones (serpulite) characterized by monospecific associations (here:
Serpula socialis
Goldfuss). Late Jurassic:
Pinkerdorf, Lower Saxony, Germany.
5
Spirobids.
These calcareous worms have distinct supporting structures (SS). The sample comes from a shallow-marine
limestone block that was transported into the deeper ocean. During deposition the block was overturned, as indicated by
the geopetal infill. Late Jurassic: Northern margin of the Calcareous Alps near Salzburg, Austria.
6
Microstructure
: Serpulid shells exhibiting the characteristic two-layered foliated microstructure with the cone-in-cone
pattern. Cretaceous: San Pietro, Mussolino, Apennines, Italy.
7
Microstructure
. The walls of the serpulid tubes consist of two microstructurally different layers (arrows). Middle Juras-
sic: Würgau, northern Franconian Alb, Germany.
8
Microstructure.
Characteristic cross section of a serpulid shell. Note the concentric, finely laminated structure. Early
Cretaceous: Ras al Khaimah, United Arabian Emirates.
9
Agglutinated worm tube.
Oblique section. Late Jurassic: Subsurface, Kinsau near Augsburg, southern Germany.
10
Agglutinated worms.
Longitudinal (LS) and cross section (CS) of
Terebella lapilloides
Münster or
Prethocoprolithus
Elliott. The silt-sized wall material is bound together by microcrystalline carbonate. Note the intensive dark color reflect-
ing the organic content of the 'wall'. The supporting lining to the burrow is typical of a loose-ground consistency of the
sediment. These worms are common in flanking beds of Upper Jurassic sponge reefs and in wackestones of deeper ramp
settings. Associations of
Terebella
and
Tubiphytes
characterize deeper, low-energy environments and are diagnostic of
regionally lowered sedimentation rates (Leinfelder et al. 1993; Schmid 1996; Schlaginweit and Ebli 1999). The burrows
are also found as reworked particles in grain- and rudstones (see Pl. 116/1). Late Jurassic: Schammental, Suebian Alb,
southern Germany.
