Miocene Cyclopid Copepod from a Saline Paleolake in Mojave, California

© 2016 M. .There are remarkably few direct fossil records of Copepoda, which implies that current estimates of the lineage divergence times and inferences on the historical biogeography remain highly dubious for these small-sized crustaceans. The Cyclopidae, a predominantly freshwater copepod family with 1000+ species and distributed worldwide, has no fossil record at all. Recent collections from the middle Miocene Barstow Formation in Southern California resulted in ample material of finely preserved cyclopid fossils, including both adult and larval stages. To document the antennulary setation pattern in the adult and copepodid instars we used a coding system that is coherent between sexes and developmental stages. The majority of the cyclopid fossils, coming from saline lake environment, represent the modern genus Apocyclops, a euryhaline, thermophilic group occurring both in the New World and Old World. A new species Apocyclops californicus is described, based on the short medial spine and spiny ornamentation of the free segment of leg 5, spinule ornamentation of pediger 5, and well-developed protuberances of the intercoxal sclerite of leg 4. The presence of antennal allobasis and the features of the swimming legs unambiguously place the Miocene Apocyclops in the A. panamensis-clade, a predominantly amphi-Pacific group. The middle Miocene fossils with clear affinities to a subgroup of Apocyclops imply an early Miocene or Paleogene origin of the genus. Based on the geographic patterns of the species richness and morphology in Apocyclops and its presumed closest relative, genus Metacyclops, we hypothesize that: (i) the ancestor of Apocyclops, similar in morphology to some cave-dweller Metacyclops occurring today in the peri-Mediterranean region, might have arrived in North America from Europe via the Thulean North Atlantic bridge in the late Paleocene-early Eocene; (ii) Eocene termination of the Thulean land connection might have resulted in the divergence of Apocyclops from the Metacyclops stock

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Miocene Cyclopid Copepod from a Saline Paleolake in Mojave, California

© 2016 M. .There are remarkably few direct fossil records of Copepoda, which implies that current estimates of the lineage divergence times and inferences on the historical biogeography remain highly dubious for these small-sized crustaceans. The Cyclopidae, a predominantly freshwater copepod family with 1000+ species and distributed worldwide, has no fossil record at all. Recent collections from the middle Miocene Barstow Formation in Southern California resulted in ample material of finely preserved cyclopid fossils, including both adult and larval stages. To document the antennulary setation pattern in the adult and copepodid instars we used a coding system that is coherent between sexes and developmental stages. The majority of the cyclopid fossils, coming from saline lake environment, represent the modern genus Apocyclops, a euryhaline, thermophilic group occurring both in the New World and Old World. A new species Apocyclops californicus is described, based on the short medial spine and spiny ornamentation of the free segment of leg 5, spinule ornamentation of pediger 5, and well-developed protuberances of the intercoxal sclerite of leg 4. The presence of antennal allobasis and the features of the swimming legs unambiguously place the Miocene Apocyclops in the A. panamensis-clade, a predominantly amphi-Pacific group. The middle Miocene fossils with clear affinities to a subgroup of Apocyclops imply an early Miocene or Paleogene origin of the genus. Based on the geographic patterns of the species richness and morphology in Apocyclops and its presumed closest relative, genus Metacyclops, we hypothesize that: (i) the ancestor of Apocyclops, similar in morphology to some cave-dweller Metacyclops occurring today in the peri-Mediterranean region, might have arrived in North America from Europe via the Thulean North Atlantic bridge in the late Paleocene-early Eocene; (ii) Eocene termination of the Thulean land connection might have resulted in the divergence of Apocyclops from the Metacyclops stock

Miocene Cyclopid Copepod from a Saline Paleolake in Mojave, California

© 2016 M. .There are remarkably few direct fossil records of Copepoda, which implies that current estimates of the lineage divergence times and inferences on the historical biogeography remain highly dubious for these small-sized crustaceans. The Cyclopidae, a predominantly freshwater copepod family with 1000+ species and distributed worldwide, has no fossil record at all. Recent collections from the middle Miocene Barstow Formation in Southern California resulted in ample material of finely preserved cyclopid fossils, including both adult and larval stages. To document the antennulary setation pattern in the adult and copepodid instars we used a coding system that is coherent between sexes and developmental stages. The majority of the cyclopid fossils, coming from saline lake environment, represent the modern genus Apocyclops, a euryhaline, thermophilic group occurring both in the New World and Old World. A new species Apocyclops californicus is described, based on the short medial spine and spiny ornamentation of the free segment of leg 5, spinule ornamentation of pediger 5, and well-developed protuberances of the intercoxal sclerite of leg 4. The presence of antennal allobasis and the features of the swimming legs unambiguously place the Miocene Apocyclops in the A. panamensis-clade, a predominantly amphi-Pacific group. The middle Miocene fossils with clear affinities to a subgroup of Apocyclops imply an early Miocene or Paleogene origin of the genus. Based on the geographic patterns of the species richness and morphology in Apocyclops and its presumed closest relative, genus Metacyclops, we hypothesize that: (i) the ancestor of Apocyclops, similar in morphology to some cave-dweller Metacyclops occurring today in the peri-Mediterranean region, might have arrived in North America from Europe via the Thulean North Atlantic bridge in the late Paleocene-early Eocene; (ii) Eocene termination of the Thulean land connection might have resulted in the divergence of Apocyclops from the Metacyclops stock

Miocene Cyclopid Copepod from a Saline Paleolake in Mojave, California

© 2016 M. .There are remarkably few direct fossil records of Copepoda, which implies that current estimates of the lineage divergence times and inferences on the historical biogeography remain highly dubious for these small-sized crustaceans. The Cyclopidae, a predominantly freshwater copepod family with 1000+ species and distributed worldwide, has no fossil record at all. Recent collections from the middle Miocene Barstow Formation in Southern California resulted in ample material of finely preserved cyclopid fossils, including both adult and larval stages. To document the antennulary setation pattern in the adult and copepodid instars we used a coding system that is coherent between sexes and developmental stages. The majority of the cyclopid fossils, coming from saline lake environment, represent the modern genus Apocyclops, a euryhaline, thermophilic group occurring both in the New World and Old World. A new species Apocyclops californicus is described, based on the short medial spine and spiny ornamentation of the free segment of leg 5, spinule ornamentation of pediger 5, and well-developed protuberances of the intercoxal sclerite of leg 4. The presence of antennal allobasis and the features of the swimming legs unambiguously place the Miocene Apocyclops in the A. panamensis-clade, a predominantly amphi-Pacific group. The middle Miocene fossils with clear affinities to a subgroup of Apocyclops imply an early Miocene or Paleogene origin of the genus. Based on the geographic patterns of the species richness and morphology in Apocyclops and its presumed closest relative, genus Metacyclops, we hypothesize that: (i) the ancestor of Apocyclops, similar in morphology to some cave-dweller Metacyclops occurring today in the peri-Mediterranean region, might have arrived in North America from Europe via the Thulean North Atlantic bridge in the late Paleocene-early Eocene; (ii) Eocene termination of the Thulean land connection might have resulted in the divergence of Apocyclops from the Metacyclops stock

Proposed mechanisms for water oxidation by Photosystem II and nanosized manganese oxides

© 2016 Elsevier B.V. Plants, algae and cyanobacteria capture sunlight, extracting electrons from H2O to reduce CO2 into sugars while releasing O2 in the oxygenic photosynthetic process. Because of the important role of water oxidation in artificial photosynthesis and many solar fuel systems, understanding the structure and function of this unique biological catalyst forms a requisite research field. Herein the structure of the water-oxidizing complex and its ligand environment are described with reference to the 1.9 Å resolution X-ray-derived crystallographic model of the water-oxidizing complex from the cyanobacterium Thermosynechococcus vulcanus. Proposed mechanisms for water oxidation by Photosystem II and nanosized manganese oxides are also reviewed and discussed in the paper