Paleozoic origins of cheilostome bryozoans and their parental care inferred by a new genome-skimmed phylogeny.

Phylogenetic relationships and the timing of evolutionary events are essential for understanding evolution on longer time scales. Cheilostome bryozoans are a group of ubiquitous, species-rich, marine colonial organisms with an excellent fossil record but lack phylogenetic relationships inferred from molecular data. We present genome-skimmed data for 395 cheilostomes and combine these with 315 published sequences to infer relationships and the timing of key events among c. 500 cheilostome species. We find that named cheilostome genera and species are phylogenetically coherent, rendering fossil or contemporary specimens readily delimited using only skeletal morphology. Our phylogeny shows that parental care in the form of brooding evolved several times independently but was never lost in cheilostomes. Our fossil calibration, robust to varied assumptions, indicates that the cheilostome lineage and parental care therein could have Paleozoic origins, much older than the first known fossil record of cheilostomes in the Late Jurassic.

A genome-skimmed phylogeny of a widespread bryozoan family, Adeonidae.

BACKGROUND: Understanding the phylogenetic relationships among species is one of the main goals of systematic biology. Simultaneously, credible phylogenetic hypotheses are often the first requirement for unveiling the evolutionary history of traits and for modelling macroevolutionary processes. However, many non-model taxa have not yet been sequenced to an extent such that statistically well-supported molecular phylogenies can be constructed for these purposes. Here, we use a genome-skimming approach to extract sequence information for 15 mitochondrial and 2 ribosomal operon genes from the cheilostome bryozoan family, Adeonidae, Busk, 1884, whose current systematics is based purely on morphological traits. The members of the Adeonidae are, like all cheilostome bryozoans, benthic, colonial, marine organisms. Adeonids are also geographically widely-distributed, often locally common, and are sometimes important habitat-builders. RESULTS: We successfully genome-skimmed 35 adeonid colonies representing 6 genera (Adeona, Adeonellopsis, Bracebridgia, Adeonella, Laminopora and Cucullipora). We also contributed 16 new, circularised mitochondrial genomes to the eight previously published for cheilostome bryozoans. Using the aforementioned mitochondrial and ribosomal genes, we inferred the relationships among these 35 samples. Contrary to some previous suggestions, the Adeonidae is a robustly supported monophyletic clade. However, the genera Adeonella and Laminopora are in need of revision: Adeonella is polyphyletic and Laminopora paraphyletically forms a clade with some Adeonella species. Additionally, we assign a sequence clustering identity using cox1 barcoding region of 99% at the species and 83% at the genus level. CONCLUSIONS: We provide sequence data, obtained via genome-skimming, that greatly increases the resolution of the phylogenetic relationships within the adeonids. We present a highly-supported topology based on 17 genes and substantially increase availability of circularised cheilostome mitochondrial genomes, and highlight how we can extend our pipeline to other bryozoans.

New encrusting species of Lanceoporidae (Bryozoa, Cheilostomata) from the southern Great Barrier Reef, Australia.

Three new species of lanceoporids from the southern Great Barrier Reef are described. Calyptotheca trimandibulata n. sp. is recorded from inter-reefal sites, Stephanotheca bahloo n. sp. is recorded from a coral reef site, and Stephanotheca kutyeri n. sp. is recorded from inter-reefal sites and also Bass Strait and the Great Australian Bight, and is therefore unusual amongst Australian lanceoporids in occurring in both tropical and temperate locations. The known variation in morphological characters is widened for both genera: C. trimandibulata n. sp. is the only known Calyptotheca species typically having three adventitious avicularia per zooid, S. bahloo n. sp. has the most pronounced orifice dimorphism and the most transversely oval primary orifice for the genus, and S. kutyeri n. sp. is distinguished by long, narrow, slit-like pseudopores in the frontal shield. All three species have occasional dimorphic autozooids, distinguished by larger orifices resembling those of the respective ovicellate zooids, and this is documented for the first time for both genera.

Three new species of Calyptotheca (Bryozoa: Lanceoporidae) from the Great Barrier Reef, tropical Australia.

The cheilostome bryozoans Calyptotheca wulguru n. sp. and Calyptotheca tilbrooki n. sp. (Lanceoporidae) are described from inter-reefal, sediment-dominated habitats of the Great Barrier Reef, and Calyptotheca churro n. sp. was washed up on a Heron Island beach, with uncertain origin. Calyptotheca wulguru n. sp. and C. churro n. sp. belong to a subgroup of Calyptotheca species with numerous small, oval, marginal adventitious avicularia and suboral nodular thickening or umbones. The vicarious avicularia of C. tilbrooki n. sp. are elongate-oval, unlike those of other known Calyptotheca species, and C. tilbrooki n. sp. has more pronounced orificial dimorphism than in any other known Calyptotheca species. Calyptotheca churro n. sp. has the most pronounced suboral umbo of all known Calyptotheca species. This study increases the known Calyptotheca species of the Great Barrier Reef to ten, and of tropical Australia to 14.

Two tropical species of Stephanotheca (Bryozoa, Cheilostomata, Lanceoporidae) from the Gulf of Carpentaria, Australia.

Two new species of Stephanotheca are described from the southeast Gulf of Carpentaria, northern Australia, providing the first tropical records of this genus. Stephanotheca ipsum n. sp. is provisionally placed in the genus on the basis of a low ridge of calcification around the edge of the ooecium, which differs from the fully pseudoporous ooecium of Calyptotheca (Lanceoporidae) and resembles the 'crowned' ooecium of Stephanotheca, with a central porous area surrounded by a nodular imperforate area. Stephanotheca ipsum and Stephanotheca romajoyae n. sp. are the only species in the genus with more than one avicularium on some zooids. The latter species is distinguished by high variability in avicularium size, shape, position and orientation; it also shares dimorphic avicularia with S. ochracea (Hincks) and is the only species in which they sometimes occur together on the same zooid. This study increases the number of Australian Stephanotheca species to four. The Australian species all have smaller primary orifices and variations in ovicell morphology compared with other, all European, species. In S. ipsum n. sp. the ooecia are ridged, those of S. victoriensis Reverter-Gil et al. have a single row of pseudopores forming an arch, and those of S. ambita (Waters) and S. romajoyae n. sp. have a relatively large pseudoporous area and smaller, lower nodular imperforate area. None of the Australian species have vicarious avicularia, which are known only from the type species, S. barrosoi Reverter-Gil et al.

Six species of Calyptotheca (Bryozoa, Cheilostomata, Lanceoporidae) from the Gulf of Carpentaria and northern Australia, with description of a new species.

A new diagnosis is presented for Calyptotheca Harmer, 1957 and six species are described from the Gulf of Carpentaria: C. wasinensis (Waters, 1913) (type species), C. australis (Haswell, 1880), C. conica Cook, 1965 (with a redescription of the holotype), C. tenuata Harmer, 1957, C. triquetra (Harmer, 1957) and C. lardil n. sp. These are the first records of Bryozoa from the Gulf of Carpentaria, and the first Australian records for C. wasinensis, C. tenuata and C. triquetra. The limit of distribution of three species is extended east to the Gulf of Carpentaria, from Kenya for C. wasinensis, from China for C. tenuata, and from northwestern Australia for C. conica. The number of tropical Calyptotheca species in Australian territorial waters is increased from seven to eleven.