Assessment of serpulid-hydroid association through the Jurassic: A case study from the Polish Basin
Fig 2
Protulophila gestroi Rovereto bioclaustrated by two species of the serpulid Propomatoceros from the Polish Jura.
A. A strongly infested Propomatoceros sp. from the Upper Bajocian of Mokrsko, exhibiting a regular arrangement of the colony. External appearance shows apertures slightly bent toward the anterior of the tube; elongation of polyp chambers to the serpulid’s growth direction is visible, GIUS 8-3730/1. B. Strongly infested Propomatoceros lumbricalis (von Schlotheim) from the Middle Bathonian of Gnaszyn Dolny. Dense arrangement of the hydroid colony shows different apertural morphologies within one specimen. Three views (two lateral and one dorsal) show hydroid colony embedment around nearly entire tube, GIUS 8-3730/2. C. Infested Propomatoceros lumbricalis from the Lower Bathonian of Kawodrza Górna, showing an irregular colony pattern with small polyp openings scattered over the tube. Aperture lips are slightly flattened, forming only indistinct hoods. A hydroid colony encircled the whole tube from the base to the keel (as shown in three views of the tube), GIUS 8-3730/3. D. A hydroid colony located in the anterior part of the tube of Propomatoceros lumbricalis from the Middle Bathonian of Gnaszyn Dolny. Single apertures are bent backward, GIUS 8-3730/4. E. Moderately infested tube from the Middle Bathonian of Gnaszyn Dolny with a relatively regular colony pattern, GIUS 8-3730/5. F-G. ESEM back-scattered images presenting detailed morphology of hydroid apertures. In F, two robust bosses overhanging the apertures (indicated by white arrows) and a few smaller hoods are shown, GIUS 8-3730/2. G indicates delicate lumps, GIUS 8-3730/1. Scale bars: 5 mm (A-E), 0.5 mm (F-G).
