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Phylum Coelenterata,
Class Anthozoa
- rugose 'horn corals' of the sub-class Tetracorallia: Solitary Tetracorals
Initial identification (based on external features - no sectioning was done)of 120 specimens from Rockford from various field trips. I.D. is from Fenton & Fenton 1924. White labels are 9 cm wide. 2 specimens on 3rd label down from upper right hand corner are unidentified. Largest specimen (T. ponderosa) is 7.8 cm long.
Viewed: 362 times.
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| Phylum Coelenterata; Class Anthoza
Initial sort of all my specimens of colonial corals: Genus Pachyphyllum (most probably are P. woodmani)
Viewed: 334 times.
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| Phylum Mollusca:
Palaeotrochid gastropods
Initial sort of 164 specimens combined from 8 field trips to the Devonian (Frasnian) shales at Rockford, Floyd County, Iowa . Virtually all these specimens are the species Floydia gigantea (with possibly a few Turbonopsis hackberryensis?).
Viewed: 314 times.
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| ... more Palaeotrochid gastropods
Display of a few additional Rockford specimens. Large specimens (max. dim. is 70 mm) show the typical collabral ornament of Floydia gigantea. Middle row specimens are casts of F. gigantea. Bottom row is Westernia pulchra (Note that specimen in lower left corner is a modern seashell!).
Viewed: 322 times.
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| ... other gastropods.
Left: Westernia pulchra (4); Center: Straparollus circinatus (1) and S. portlandensis (4); Right: Belerophon sp. (12) in various views.
Viewed: 311 times.
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Phylum Mollusca;
Class Pelecypoda
Initial sort from all collections. These 'clams' had shells of aragonite which was not preserved. Fossils are weathered casts of the inside of the bivalve shell, so are difficult to identify. Based on Fenton & Fenton (1924)there are: 3 forms of Paracyclas sabini, and typical Grammysis(?) dubia.
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| Phylum Mollusca
Class Pelecypoda (Lamellibranchia)
?? Grammysia dubia Fenton 1924
All specimens are internal casts of the shell - here shown is left valve view of select specimens. L=left valve, R=single specimen right valve. Customary orientation is to view specimen along line of symmetry (between the valves) with hinge line uppermost and beaks (umbo) directed away (maybe only a slight indication) to the anterior. The right valve is then to the right (and the posterior is up!).
Viewed: 313 times.
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| ?? Grammysia dubia
posterio-dorsal view all specimens.
Note: many specimens are casts of the ventral portion of the articulated shell. Orientation is based on slight difference of profile posterior-to-anterior when compared to a whole specimen.
Viewed: 314 times.
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| ?? Grammysia dubia
anterio-ventral view all specimens. There seems to be a difference among the specimens in the length-to-thickness ratio - perhaps a sub-sort is needed?
Viewed: 298 times.
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| Phylum: Mollusca
Class: Cephalopoda
Subclass: Nautiloidea
Order: Michelinoceratida
Shown here is initial sort of all specimens of 2 'orthoconic' cephalopod species once named 'Orthoceras. Species (lf-to-rt): (Orthoceras) sp.1, and sp.2 Fenton & Fenton 1924. Note: I just added 1 more of O. sp. 1, not pictured.
Viewed: 297 times.
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Phylum Echinoderma
Subphylum Pelmatozoa
Class Crinoidea
...initial sort of all specimens
Viewed: 289 times.
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| Phylum: Bryozoa
Subphylum: Ectoprocta
Class: Stenolaemata
Order: Trepostomata
Family: Batostomellidae
Genus: Lioclema
Initial sort of L. occidens, an irregularly branching massive to frond-like calcareous colony of microscopic 'autozoids'. These are typical broken fragments of the colony.
Viewed: 326 times.
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| ...more Initial sort Lioclema. Ok, thought I'd have no regrets about my collecting at Rockford. But, I promise, I will never bring back another Lioclema. The Rockford brachiopods and horn corals seemed are almost unlimited in their 'speciation', but old Lioclema seems to be monolithic as a species (and I'm not yet willing to do the 'peals' to try to see if it can be split further...)
Viewed: 316 times.
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| other bryozoans, initial sort. Note: 'inch' scale here. Middle row is the Fentons' Cladopora floydensis, but they defined it as occurring not at Rockford, but in the Owen Formation stratigraphically above (and therefore next younger) then the Cerro Gordo shales at Rockford. Top row is Fenestella; bottom is (well, I working on it...).
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| Larger fossils are frequently encrusted with smaller fossils called Epibiodonts. here are a few including probably: branching bryozoans (Hederella), inarticulate brachiopods (Crania), branching corals (Aulopora).
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Phylum: Annelida
Class: Polychaeta
Order: Eunicida
Family: various.
Scolecodonts are individual elements of the jaw aparatus of marine worms. The element shown is actually 0.75 mm long. I have isolated 50-60 elements, so far.
Viewed: 301 times.
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| Kingdom: Chlorobionta
Division: Charophyta
Subdivision: Streptophytina
Class: Charophyceae
Order: ? Sycidiales
These 'charophytes' are technically the 'fructification of algae', more specifically gametangia (fertile elements) and more specifically, oogonia preserved as the dentrally spiraled protective sheath of female gametangia. They are .3-.5 mm in size. Basically they belong to fossil algae (land 'plants' living in fresh water) and have been preserved because of an original calcareous composition. Three tytpical specimens shown. The pin shaft is 0.65 mm in dia.
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| Phylum: Arthropoda
Class: Ostracoda
A marine crustacean. One specimen is shown here, second from the left, in this microfossil composite which includes from left to right: scolecodont, ostracode, scolecodont, 2 charophytes, and a quartz sand grain. All specimens shown are less then 1 mm in size.
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| Rockford clay pit: view to southwest of south pit near the Park entrance. The lower formation (from quarry bench to beneath the pond)is the Juniper Hill member, with the lower Cerro Gordo just above and to the ground surface. The Juniper Hill contains few fossils. Photo taken in Sept 1999.
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| Typical collecting site at the Rockford clay pit: a spoil slope of Cerro Gordo Member shale. Most specimens were simply picked up off this surface. Occasionally a large specimen needed a little coaxing...
Viewed: 338 times.
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