The marine biota from the middle Pennsylvanian outcrops of the Sierra Agua Verde, located in mid-eastern Sonora, consists of phylloid algae of the genera Komia and Eugonophyllum and a number of invertebrates. These species include bioaccumulations of chaetetids; brachiopods of the genera Dielasma sp., Reticulariina sp., Anthracospirifer sp., Antiquatonia sp.; bryozoans of the genus Thamniscus; tabulate corals such as Syringopora and solitary corals such as Zaphrentis; fusulinid foraminifera such as Pseudostaffella, Eoshubertella texana, Fusulinella llanoensis, and Zellerella; gastropods of the genus Euomphalus and Donaldina; and the crinoid genera Cyclocaudex, Cyclocrista, Heterosteleschus, Lamprosterigma, Mooreanteris, Pentagonopternix, Preptopremium, Cycloscaspus, and Pentaridica. The material was collected from outcrops in the first 512m of the La Joya Formation, and their sediments have a total thickness of 780m and consist of limestone interbedded with calcareous mudstone and sandstone lenses. The age of the middle Pennsylvanian strata corresponds to that of the Atokan stage (311 million years). The species assemblages are typical of a shallow tropical marine benthos. The analysis of the distribution of the species allowed for the determination of their paleogeographic relationships with the components of the biota of the Carboniferous strata of Texas and Kansas in the United States of America, which belong to the province of the North American Craton.

The bioerosion trace fossils are described from the Pliocene cropping out at the Agua Amarga Subbasin (Betic Cordillera, Almería Province, SE Spain). They are associated with limestone clasts (pebbles and cobbles) and molluscs constituting a shallow marine conglomerate and an overlying composite shell bed that were deposited in a shallow marine setting. The ichnotaxa include borings produced by sponges (Entobia cateniformis, E. geometrica, E. laquea, E. form A and E. form B), bivalves (Gastrochaenolites torpedo, and G. lapidicus) and polychaete annelids (Caulostrepsis taeniola, Meandropolydora ?decipiens, M. cf. elegans, and M. cf. sulcans). Encrustations by bryozoans and tube annelids are also present. The bioerosion trace fossils assemblages from the conglomerate and the shell bed can be ascribed to the Entobia subichnofacies, which is typical of Neogene rocky-shore settings. Bioerosion analysis allows improved interpretation of palaeoenvironmental (ecological and depositional) conditions i.e. hydrodynamic energy, rate of sedimentation, and exposure time, in the Agua Amarga Subbasin during the Pliocene.