A First Account of Freshwater Potamolepid Sponges (demospongiae, Spongillina, Potamolepidae) from the Middle Eocene: Biogeographic and Paleoclimatic Implications
نویسندگان
چکیده
We report the oldest fossil occurrence of freshwater potamolepid sponges (Demospongiae, Spongillina, Potamolepidae) to date, originating from middle Eocene lake sediments accumulated in the Giraffe kimberlite maar, northern Canada. Sponges are represented by strongyle spicules that are gemmuloscleres. These are described herein as belonging to a new species, Potamophloios canadensis. Because the most similar extant potamolepid sponges inhabit subtropical to tropical water bodies, these observations provide further evidence of biogeographic reorganizations in response to warm high-latitude Eocene paleoclimates.
منابع مشابه
Endemic Lake Baikal sponges from deep water. 1: Potential cryptic speciation and discovery of living species known only from fossils.
We revealed new deep-water species and cryptic speciation within freshwater sponges of the endemic family Lubomirskiidae (Porifera; Demospongiae; Spongillina) based on molecular and spicule morphology analyses of ITS and CO1 mtDNA. Lubomirskiidae contains a group of closely related species which are a dominant component of the benthos in Lake Baikal, the world's deepest and most ancient lake. S...
متن کاملDiscovery of living Potamolepidae (Porifera: Spongillina) from Nearctic freshwater with description of a new genus.
We report here the first record of a living Potamolepidae (Cherokeesia n. gen.) from the Nearctic Region and from the northern hemisphere. The new species Cherokeesia armata from southern Appalachians diverges at generic and specific level from all the other known taxa of the family Potamolepidae in its unique combination of diagnostic traits: gemmular theca armed by gemmuloscleres ranging from...
متن کاملNew Approaches to Study Biodiversity and Evolution of Freshwater Sponges in Ancient Lakes
Freshwater sponges (Porifera; Spongillina) include 6 families. Some of them are endemic of ancient lakes Baikal, Tanganyika, Ohrid and Malawi. Others families are cosmopolitan and inhabit inland waters worldwide. Freshwater sponges are important for cleaning of water due their filter activity and are often main part of benthos in the lakes. The taxonomy of freshwater sponges is difficult that c...
متن کاملBiodiversity of freshwater sponges (Porifera: Spongillina) from northeast Brazil: new species and notes on systematics.
Systematics and distribution of freshwater sponges is still poorly understood worldwide. This may be due to the scarcity of records, and the limited information about morphological traits used for taxonomy. Brazil has reportedly high species richness in the Neotropical Region; however, this diversity is likely to be significantly underestimated given that there are still many unexplored and poo...
متن کاملTropical Ochrophyte Algae from the Eocene of Northern Canada: a Biogeographic Response to past Global Warming
We report on exquisitely preserved specimens of freshwater siliceous algae belonging to the classes Synurophyceae (scaled chrysophytes) and Bacillariophyceae (diatoms) from middle Eocene lake sediments in Northern Canada. When considered in the context of closest extant relatives, these microfossils present unequivocal biogeographic and ecological affinities with warm-water ochrophyte assemblag...
متن کامل