Generalizations of the short pulse equation

We classify integrable scalar polynomial partial differential equations of second order generalizing the short pulse equation

Data from: From incipient to substantial: evolution of placentotrophy in a phylum of aquatic colonial invertebrates

Matrotrophy has long been known in invertebrates, but it is still poorly understood and has never been reviewed. A striking example of matrotrophy (namely, placentotrophy) is provided by the Bryozoa, a medium-sized phylum of the aquatic colonial filter feeders. Here I report on an extensive anatomical study of placental analogues in 21 species of the bryozoan order Cheilostomata, offering the first review on matrotrophy among aquatic invertebrates. The first anatomical description of incipient placentotrophy in invertebrates is presented together with the evidence for multiple independent origins of placental analogues in this order. The combinations of contrasting oocytic types (macrolecithal or oligolecithal) and various degrees of placental development and embryonic enlargement during incubation, found in different bryozoan species, are suggestive of a transitional series from the incipient to the substantial placentotrophy accompanied by an inverse change in oogenesis, a situation reminiscent of some vertebrates. It seems that matrotrophy could trigger the evolution of sexual zooidal polymorphism in some clades. The results of this study show that this phylum, with its wide variety of reproductive patterns, incubation devices and types of the simple placenta-like systems, offers a promising model for studying parallel evolution of placentotrophy in particular, and matrotrophy in general

Table-DRYAD

Data file contains a list of cheilostome bryozoan species and their reproductive patterns describing their oogenesis mode, absence and presence of brooding and its mode (placental vs non-placental

Omanipora pilleri nov. gen. nov. spec., a new lepraliomorph bryozoan (Cheilostomata) from Oman

Abstract Bryozoans from around the Arabian Peninsula are only poorly known. Here we describe a new cheilostome taxon, Omanipora pilleri nov. gen. nov. spec., from the western Indian Ocean, south of the town of Duqm (eastern central Oman). Starting from an encrusting base the colonies grow erect, producing either branching and anastomosing bilaminar fronds or robust radial branches by means of frontal budding, while some specimens even exhibit an intracolonial morphological gradient from one branch type to the other. The variability in colony morphology presumably reflects growth under different hydrodynamic conditions. Based on superficially similar orificial, ooecial, avicularian and frontal wall structures the new taxon is tentatively placed within the Celleporidae JOhnstOn. Some of the characters that justify the introduction of a new genus are: communication of the ooecial coelomic cavity with the maternal zooid proceeds via several distal communication pores, which is a feature that has not been observed before; ovicell closure is of the cleithral type; and the orifices are dimorphic in fertile (egg-producing) and non-fertile zooids. Keywords: Bryozoa, Indian Ocean, new species, new genus, ovicells. Zusammenfassung Die Bryozoen der Arabischen Halbinsel sind immer noch sehr unzureichend bekannt. In der vorliegenden Arbeit wird ein neues Taxon cheilostomer Bryozoen aus dem westlichen Indischen Ozean beschrieben, das an der Ostküste des zentralen Oman (südlich des Ortes Duqm) vorkommt

Pre-Cenomanian Cheilostome Bryozoa : Current State of Knowledge

This paper briefly summarizes published and new data on the occurrences of pre-Cenomanian cheilostome Bryozoa following their first appearance in the Late Jurassic. We tabulate all known taxa chronologically, summarize stratigraphical and geographical distributions, and comment on the main morphological innovations that appeared in pre-Cenomanian times. Most early cheilostomes are classified in the suborder Malacostegina. Early cheilostomes were morphologically simple and low in diversity, but were geographically widespread. These features can be explained by the possession of a long-living planktotrophic larval stage, as in Recent malacostegans. Diversification of the suborder Neocheilostomina, which greatly dominates modern and post-Albian bryozoan faunas, began in the Late Albian and coincided with the origin of brood chambers (ovicells) and a presumably short-lived, non-planktotrophic larva. The presence of Late Albian neocheilostomes in both Europe and North America implies that their brief larval life was not an obstacle to achieving a wide distribution and suggests a role for rafting in their dispersal.International Symposium, "The Origin and Evolution of Natural Diversity". 1–5 October 2007. Sapporo, Japan

Crepis longipes Jullien 1882

Crepis longipes Jullien, 1882 (Figs 18–22, Table 6) Crepis longipes Jullien, 1882: 522, pl. 17, figs 60, 61; Prenant & Bobin 1966: 366, fig. 119; d’Hondt 1973 a: 367; 1974: 29; Reverter-Gil et al. 2011: 2, figs 1-4; Souto et al. 2014: 136, fig. 3 C, D. Material examined. MNCN 25.03 / 3932, locality DW 110; MNHN IB- 2013 - 622, locality DW 117. Remarks. Reverter-Gil et al. (2011) recently redescribed type and other material of Crepis longipes from the Iberian continental shelf. Although the authors stated that one of the Travailleur stations from which Jullien (1882) originally recorded the species was Galicia Bank, this was a mistake owing to a wrong interpretation of the geographic position. During the Travailleur campaign the longitude was referenced to the Paris meridian, which nowadays makes it necessary to correct the original reading to the Greenwich meridian (Ryland 1969). After corrections, that station is situated on the continental slope of northern Iberia. Nevertheless, we are able to demonstrate here that C. longipes does, indeed, occur on Galicia Bank, which marks the first record of this species off the continental shelf. SD, standard deviation; N, number of measurements Souto et al. (2014) described the ovicell and operculum of C. longipes for the first time; both characters were also observed in the specimens from Galicia Bank (Figs 18, 19, 22), and are identical with the previously recorded material. Ovicells are terminal, the ooecium being formed by a distal kenozooid that is concealed from frontal view, and which distally buds the caudal part of the next autozooid in a row. Several specimens were found at four Galicia Bank localities ranging from 770 to 860 m depth. The colonies mainly encrust coral skeletons but also rocks, while one colony was found on a piece of slightly lithified foraminiferal sand.Published as part of Souto, Javier, Berning, Björn & Ostrovsky, Andrew N., 2016, Systematics and diversity of deep-water Cheilostomata (Bryozoa) from Galicia Bank (NE Atlantic), pp. 401-459 in Zootaxa 4067 (4) on pages 412-413, DOI: 10.11646/zootaxa.4067.4.1, http://zenodo.org/record/25794

Galiciapora unica Souto, Berning & Ostrovsky, 2016, n. sp.

Galiciapora unica n. sp. (Figs 114–118, Table 20) Material examined. Holotype: MNCN 25.03 / 3976, locality DR04. Paratypes: MNCN 25.03 / 3977, locality DR01; MNCN 25.03 / 3978, locality DR02; MNCN 25.03 /3979, 3980, locality DR03; OLL 2015 / 919, locality DR03; OLL 2015 / 920, locality DR01. Etymology. Latin unicus, only, single, alluding to the single zooids in uniserial chains. Description. Colony encrusting, uniserial, branching at an angle of c. 40–50 °. Zooids oval, large, frontal shield convex with smooth surface texture, entirely covered by about 150 pseudopores right up to prominent, widely flaring peristome, distal part of peristome not formed in ovicellate zooids; vertical walls not developed laterally, but 2 distolateral basal pore-chambers present, well-marked by raised borders, each with paired communication pores from which 1–2 zooids may be budded on either or both sides; central distal area in between has single pore through which communication with ooecium-producing distal kenozooid is established when budded. Orifice a little longer than wide, widest in distal third, anter roughly horseshoe-shaped, proximal margin with broad, shallow U-shaped sinus, condyles rather small, smooth. Peristome thick-walled, flared, with paired lateral adventitious avicularia. Avicularia adventitious, small, paired, incorporated into lateral rim of peristome, oval in outline, rostrum semielliptical, directed distolaterally, crossbar complete, without columella, palatal foramen and postmandibular opesia rounded, the latter smaller, both with cryptocystal shelf. Ovicell terminal, prominent; ooecium formed by flat distal kenozooid budded from distal uniporous pore chamber of maternal zooid, longer than wide; ectooecium smooth, frontally flattened with 25–30 pseudopores of variable shape and size, proximal area concave, paralleling margin of zooidal orifice, lateral margins abutting peristome. An ancestrula not observed. SD, standard deviation; N, number of measurements Remarks. This species is yet another uniserial encrusting ascophoran cheilostome described from bathyal depths. As in many of the other uniserial species, and in contrast to multiserial species from shallow waters, the zooids are relatively large, the lateral walls are greatly reduced and the ooecium is formed by a distal kenozooid, not by a distal autozooid. These characters have seemingly evolved as adaptations for bathyal conditions independently in numerous clades as the uniserial growing species are distributed over different superfamilies. It is also possible that many have a long evolutionary history as it is often difficult or impossible to determine sister taxa. The systematic position of uniserial ascophorans is therefore often fairly isolated, leading to the existence of several monspecific genera [e.g. Nimbella with N. limbata Jullien & Calvet, 1903; Sertulipora with S. guttata Harmelin & d'Hondt, 1992; Cheilonellopsis with C. inflata Gordon, 2014; Placidoporella n. gen. with P. insperata (Jullien, 1882)]. Sertulipora guttata was described from the Gibraltar Strait region based on four specimens designated as a holotype and three paratypes (Harmelin & d’Hondt 1992). Later, Tricart & d’Hondt (2009) indicated another paratype with the number MNHN- 19792 from the Bay of Biscay. This designation is invalid because the location and specimen were not included in the original description; further, examination of the specimen showed that it is not S. guttata and could belong to the genus Galiciapora. A detailed study of the specimen is required, however, to come to a definite conclusion about its specific identity. Galiciapora unica was found at five stations between 1138 and 1697 m depth, encrusting corals and rocks.Published as part of Souto, Javier, Berning, Björn & Ostrovsky, Andrew N., 2016, Systematics and diversity of deep-water Cheilostomata (Bryozoa) from Galicia Bank (NE Atlantic), pp. 401-459 in Zootaxa 4067 (4) on pages 448-449, DOI: 10.11646/zootaxa.4067.4.1, http://zenodo.org/record/25794

Smittoidea celestinoi Souto, Berning & Ostrovsky, 2016, n. sp.

Smittoidea celestinoi n. sp. (Figs 95–98, Table 17) Material examined. Holotype: MNCN 25.03 / 3964, locality DR05. Paratypes: MNCN 25.03 / 3965, locality DR05, MNCN 25.03 / 3966, locality DR04; OLL 2015 / 912, locality DR02; OLL 2015 / 913, locality DR04. Etymology. Honorific for the first author's father, Celestino Souto-Dopico. Description. Colony encrusting, unilaminar, pluri- to multiserial, forming small patch or linear runner. Zooids elongate-oval to hexagonal or triangular, often widest in proximal third, separated by shallow grooves or ridges; frontal shield only very slightly convex, producing 2 steeply rising flaps lateral to orifice, forming peristome that incorporates suboral avicularium within proximomedian notch; surface of frontal shield nodular, large central area imperforate with 1–2 two rows of densely spaced areolae along zooecial margins; vertical walls extensive, with 1 or more uniporous septula per lateral wall. Orifice suboval, distinctly longer than wide, distal margin usually with 4 oral spines (rarely 3) in adult zooids and up to 7 spines in early astogenetic zooids; condyles acute, directed (proximo-) medially, lyrula varying in shape from rounded narrow denticle to quadrangular, generally relatively short and narrow. Ovicells hyperstomial, ooecium formed by distal zooid, globular, with slightly flattened roof, ectooecium smooth with numerous rimmed, usually circular pseudopores, proximal area concave and laterally abutting peristomial flaps; 4–5 spine bases present in fertile zooids near ovicell opening. Avicularium adventitious, single, suboral, small, proximally directed, frontal area semi-elliptical with parallel lateral margins and relatively straight proximal margin where it abuts peristome; rostrum semielliptical with broad immersed cryptocystal shelf, palatal foramen semicircular, postmandibular opesia slit-like, crossbar complete without columella. Ancestrula not observed. SD, standard deviation; N, number of measurements. Remarks. As with Smittina, species of the diverse and globally occurring genus Smittoidea essentially occur from the inner to outer shelf. There are hardly any records from bathyal depths in temperate European waters. Smittoidea reticulata (J. MacGillivray, 1842) was reported from the Iberian shelf between 20 and 240 m (Reverter- Gil & Fernández-Pulpeiro 2001; Reverter-Gil et al. 2014), but there are several differences between it and the Galicia Bank specimens—in the former the orifice is wider than long, only two distal spines are present and the suboral avicularium has an acute rostrum. Smittoidea marmorea (Hincks, 1877), supposedly occurring from the British Isles in the north to Madeira in the south (Hayward & Ryland 1999, p. 268), differs in having a broader lyrula, a larger and more proximally positioned avicularium and no oral spines in adult zooids. Two other species [S. ophidiana (Waters, 1879) from the Mediterranean Sea, and the hitherto unrecognised S. oratavensis (Busk, 1884) from the Azores] have, among other distinctive features, much longer avicularia that touch the distal part of the proximally positioned ooecium. Smittoidea celestinoi n. sp. was recorded at seven of the Galicia Bank localities from 938 to 1414 m depth, encrusting rocks, corals and shells.Published as part of Souto, Javier, Berning, Björn & Ostrovsky, Andrew N., 2016, Systematics and diversity of deep-water Cheilostomata (Bryozoa) from Galicia Bank (NE Atlantic), pp. 401-459 in Zootaxa 4067 (4) on pages 439-441, DOI: 10.11646/zootaxa.4067.4.1, http://zenodo.org/record/25794

Hippothoa longicauda Souto, Berning & Ostrovsky, 2016, n. sp.

Hippothoa longicauda n. sp. (Figs 52–59, Table 11) Material examined. Holotype: MNCN 25.03 / 3944, locality DR09. Paratypes: MNCN 25.03 / 3945, locality DR09; MNCN 25.03 / 3946, locality V01; MNHN IB- 2013 - 623, locality DW 117; OLL 2015 / 902, 903, locality DW 117. Etymology. Alluding to the extremely long zooidal cauda characteristic of this species. Description. Colony encrusting, uniserial. Zooids elongate-oval, with long thin cauda several times longer than length of autozooid, with transition from zooidal dilatation to cauda fairly abrupt, similar to transition the cauda of distal zooid; frontal shield convex, smooth or with transverse wrinkles, rising towards zooidal orifice, distal wall obliquely or vertically descending immediately distal to it; in dilated part of zooid lateral walls have 1 pair of basal pore-chambers from which thread-like caudae are produced at angle of 70–90 °, basal pore-chambers in lateral walls normally situated slightly distal to midlength of autozooid. Orifice surrounded by distinctly elevated rim, inclined frontalwards distally, longer than wide, anter horseshoe-shaped, poster wide and deep, U-shaped, delimited from anter by pair of small rounded condyles. Female zooids approximately half size of infertile zooids and with shorter cauda. Ovicell terminal, prominent, cleithral. Ooecium formed by subjacent kenozooid not visible frontally, about same size as maternal zooid. Ectooecium smooth with a few faint longitudinal striations including a median suture visible only by SEM. No distal budding from ooecial kenozooid observed. Transversely oval orifice of ovicellate zooids dimorphic, as wide as long, with wide shallow sinus and fairly long, narrow condyles that extend along straight lateral shoulders. Zooeciules not seen in the available material and may not be present in this species. Ancestrula not observed. Remarks. Only two species of Hippothoa were previously thought to occur in this region— H. divaricata Lamouroux, 1821 and H. flagellum Manzoni, 1870 (e.g. Reverter-Gil & Fernández-Pulpeiro 2001). Both are considered to be shallow-water species and allegedly have a very extensive geographic distribution while their type localities are in the Mediterranean Sea. The types of both species are presumably lost and the taxa therefore illdefined. Even within Europe, however, there are morphological differences between populations, as evidenced by a comparison of orifice shape in H. flagellum from Great Britain (Hayward & Ryland 1999, fig. 17 C) with that in an Adriatic population (Hayward & McKinney 2002, fig. 18 H), suggesting either some variability between populations or that the genus is more speciose than previously acknowledged. A revision of the genus Hippothoa combining morphological and genetic analyses is urgently needed. While Hippothoa longicauda n. sp. distinctly differs from the species generally considered to be H. divaricata in that it lacks the median keel on the autozooidal frontal shield and has dimorphic orifices in ovicellate and nonovicellate zooids, it is very closely related to H. flagellum. Orifice morphology in ovicellate and non-ovicellate zooids in our material are almost identical to specimens from Great Britain (Ryland & Gordon 1979, fig. 3; Hayward & Ryland 1999, fig. 17 C), although the autozooidal orifices are slightly longer and more distally positioned in H. longicauda. More significant differences exist, however, in the position of the orifice, which is reported to be placed beyond the highest point of the autozooid, and is orientated parallel to the substratum or sloping downwards distad, in H. flagellum (Hayward & Ryland 1999). In contrast, in H. longicauda the orifice is elevated, forming the highest point of the autozooid, and it is inclined upwards distad. Zooeciules were not observed in the available material of H. longicauda; if these are truly absent it would mark another difference between the two species. As the name implies, H. longicauda is also characterised by developing caudae that are much longer than in any of the shallow-water species. If this character is genetically determined, however, or produced as a response to environmental conditions, is unclear at present. In a settlement panel experiment recently carried out in the Azores (Wisshak et al. 2015), the single Hippothoa species present developed longer caudae with increasing depth (B. Berning pers. observ.). Hippothoa longicauda was exclusively found on coral skeletons in five Galicia Bank localities from 765 to 835 m depth. SD, standard deviation; N, number of measurementsPublished as part of Souto, Javier, Berning, Björn & Ostrovsky, Andrew N., 2016, Systematics and diversity of deep-water Cheilostomata (Bryozoa) from Galicia Bank (NE Atlantic), pp. 401-459 in Zootaxa 4067 (4) on pages 424-426, DOI: 10.11646/zootaxa.4067.4.1, http://zenodo.org/record/25794