Shark tales: a molecular species-level phylogeny of sharks (Selachimorpha, Chondrichthyes)

Sharks are a diverse and ecologically important group, including some of the ocean's largest predatory animals. Sharks are also commercially important, with many species suffering overexploitation and facing extinction. However, despite a long evolutionary history, commercial, and conservation importance, phylogenetic relationships within the sharks are poorly understood. To date, most studies have either focused on smaller clades within sharks, or sampled taxa sparsely across the group. A more detailed species-level phylogeny will offer further insights into shark taxonomy, provide a tool for comparative analyses, as well as facilitating phylogenetic estimates of conservation priorities. We used four mitochondrial and one nuclear gene to investigate the phylogenetic relationships of 229 species (all eight Orders and 31 families) of sharks, more than quadrupling the number of taxon sampled in any prior study. The resulting Bayesian phylogenetic hypothesis agrees with prior studies on the major relationships of the sharks phylogeny; however, on those relationships that have proven more controversial, it differs in several aspects from the most recent molecular studies. The phylogeny supports the division of sharks into two major groups, the Galeomorphii and Squalimorphii, rejecting the hypnosqualean hypothesis that places batoids within sharks. Within the squalimorphs the orders Hexanchiformes, Squatiniformes, Squaliformes, and Pristiophoriformes are broadly monophyletic, with minor exceptions apparently due to missing data. Similarly, within Galeomorphs, the orders Heterodontiformes, Lamniformes, Carcharhiniformes, and Orectolobiformes are broadly monophyletic, with a couple of species 'misplaced'. In contrast, many of the currently recognized shark families are not monophyletic according to our results. Our phylogeny offers some of the first clarification of the relationships among families of the order Squaliformes, a group that has thus far received relatively little phylogenetic attention. Our results suggest that the genus Echinorhinus is not a squaliform, but rather related to the saw sharks, a hypothesis that might be supported by both groups sharing 'spiny' snouts. In sum, our results offer the most detailed species-level phylogeny of sharks to date and a tool for comparative analyses.     

Timing of deep‐sea adaptation in dogfish sharks: insights from a supertree of extinct and extant taxa

Klug, S. & Kriwet, J. (2010). Timing of deep‐sea adaptation in dogfish sharks: insights from a supertree of extinct and extant taxa. —Zoologica Scripta, 39, 331–342. Dogfish sharks (Squaliformes) constitute a monophyletic group of predominantly deep‐water neoselachians, but the reasons and timing of their adaptation to this hostile environment remain ambiguous. Late Cretaceous dogfish sharks, which generally would be associated with deep‐water occur predominantly in shallow water environments. Did the end‐Cretaceous mass extinction event that eliminated large numbers of both terrestrial and aquatic taxa and clades including sharks trigger the evolutionary adaptation of present deep‐water dogfish sharks? Here, we construct, date, and analyse a genus‐level phylogeny of extinct and living dogfish sharks to bring a new perspective to this question. For this, eleven partial source trees of dogfish shark interrelationships were merged to create a comprehensive phylogenetic hypothesis. The resulting supertree is the most inclusive estimate of squaliform interrelationships that has been proposed to date containing 23 fossil and extant members of all major groups. ?Eoetmopterus represents the oldest dalatoid. ?Microetmopterus, ?Paraphorosoides, ?Proetmopterus and ?Squaliogaleus are stem‐group dalatoids in which bioluminescence most likely was not developed. According to our analyses, bioluminescence in dogfish sharks was already developed in the early Late Cretaceous indicating that these sharks adapted to deep‐water conditions most likely at about 100 Mya. The advantage of this reconstruction is that the fossil record is used directly for age node estimates rather than employing molecular clock approaches.     

Dental structure of the Giant lantern shark <Emphasis Type="Italic">Etmopterus baxteri</Emphasis> (Chondrichthyes: Squaliformes) and its taxonomic implications

Dogfish sharks (Squaliformes) are a highly diverse group of neoselachians occurring in a wide range of marine environments and are common members of deep-sea faunas. The order Squaliformes comprises six families with approximately 98 extant species. The dentition of most squaliforms is characterized by a strong dignathic heterodonty and dental variation yielding a suite of potential tooth characters that could be used for taxonomic and systematic purposes. So far, no detailed study has been carried out to analyse the use of tooth morphologies in reconstructing the phylogeny of squaliforms. Also, the degree of characteristics of intraspecific variability of tooth morphologies is still unclear. Here, we analysed the dental differences between juveniles and adults and between the sexes of the Giant lantern shark, Etmopterus baxteri, and tested these dental characters for taxonomic purposes employing different statistical procedures. The results show that upper teeth of adult females and males differ morphologically in that those of females are bigger and display a lanceolate central cusp, whereas male specimens have thin and needle-like central cusps. Upper teeth of males have a higher number and a more pronounced variability of lateral cusplets than those of females. Moreover, an ontogenetic heterodonty might be developed in male specimens with sexually immature males displaying similar dental morphologies to those of adult females. Lower teeth, conversely, do not differ morphologically between the sexes. Results indicate that tooth morphologies of squaliform sharks bear high potential for phylogenetic purposes if tooth variations are considered, but have to be treated with care, if no variation is analysed.     

Molecular phylogeny of the prickly shark, Echinorhinus cookei, based on a nuclear (18S rRNA) and a mitochondrial (cytochrome b) gene.

The classification of the sharks is unclear. This is particularly true for the superorder Squalomorphii. The relationships between the squalomorphs and other superorders of sharks and the relationships between the different orders within the squalomorphs are a matter of debate. Here, we report a molecular phylogeny for a little known member of this superorder, the genus Echinorhinus. Echinorhinus is most commonly classified in either the family Echinorhinidae (Squaliformes) or the family Squalidae (Squaliformes). However, some authors have suggested a closer relationship to the order Hexanchiformes. In an attempt to shed light on this controversy, we have cloned, sequenced, and compared two genes widely used in molecular phylogeny studies, the cytochrome b and the 18S rRNA from the rare prickly shark, Echinorhinus cookei, and two potential relatives, the spiny dogfish Squalus acanthias (Squaliformes), and the sevengill shark, Notorynchus cepedianus (Hexanchiformes). The sequences of these genes for the prickly shark, the dogfish, and the sevengill shark were found to be equally divergent, suggesting that the prickly shark is no closer to the order Squaliformes than to the order Hexanchiformes.     

Monophyly, phylogeny and systematic position of the †Synechodontiformes (Chondrichthyes, Neoselachii)

Klug, S. (2009). Monophyly, phylogeny and systematic position of the †Synechodontiformes (Chondrichthyes, Neoselachii). — Zoologica Scripta, 39 , 37–49.
Identifying the monophyly and systematic position of extinct sharks is one of the major challenges in reconstructing the phylogeny and evolutionary history of sharks in general. Although great progress has been accomplished in the last few decades with regard to resolving the interrelationships of living sharks, a comprehensive phylogeny identifying the systematic position of problematic or exclusively fossil taxa is still lacking. Fossil taxa traditionally assigned to synechodontiform sharks are very diverse with a fossil record extending back into the Palaeozoic but with uncertain inter- and intrarelationships. Here, phylogenetic analyses using robust cladistic principles are presented for the first time to evaluate the monophyly of this group, their intrarelationships and their systematic position within Neoselachii. According to the results of this study, taxa assigned to this group form a monophyletic clade, the †Synechodontiformes. This group is sister to all living sharks and displays a suite of neoselachian characters. Consequently, the concept of neoselachian systematics needs to be enlarged to include this completely extinct group, which is considered to represent stem-group neoselachians. The origin of modern sharks can be traced back into the Late Permian (250 Mya) based on the fossil record of †Synechodontiformes. The systematic position of batoids remains contradictory, which relates to the use of different data (molecular vs. morphological) in phylogentic analyses.     

Early evolution and historical biogeography of fishflies (Megaloptera: Chauliodinae): implications from a phylogeny combining fossil and extant taxa

Fishflies (Corydalidae: Chauliodinae) are one of the main groups of the basal holometabolous insect order Megaloptera, with ca. 130 species distributed worldwide. A number of genera from the Southern Hemisphere show remarkably disjunctive distributions and are considered to be the austral remnants or "living fossils" of Gondwana. Hitherto, the evolutionary history of fishflies remains largely unexplored due to limited fossil record and incomplete knowledge of phylogenetic relationships. Here we describe two significant fossil species of fishflies, namely Eochauliodes striolatus gen. et sp. nov. and Jurochauliodes ponomarenkoi Wang & Zhang, 2010 (original designation for fossil larvae only), from the Middle Jurassic of Inner Mongolia, China. These fossils represent the earliest fishfly adults. Furthermore, we reconstruct the first phylogenetic hypothesis including all fossil and extant genera worldwide. Three main clades within Chauliodinae are recognized, i.e. the Dysmicohermes clade, the Protochauliodes clade, and the Archichauliodes clade. The phylogenetic and dispersal-vicariance (DIVA) analyses suggest Pangaean origin and global distribution of fishflies before the Middle Jurassic. The generic diversification of fishflies might have happened before the initial split of Pangaea, while some Gondwanan-originated clades were likely to be affected by the sequential breakup of Pangaea. The modern fauna of Asian fishflies were probably derived from their Gondwanan ancestor but not the direct descendents of the Mesozoic genera in Asia.     

Plastomes of Betulaceae and phylogenetic implications

Betulaceae is a well‐defined family of Fagales, including six living genera and more than 160 modern species. Species of the family have high ecological and economic value for the abundant production of wood. However, phylogenetic relationships within Betulaceae have remained partly unresolved, likely due to the lack of a sufficient number of informative sites used in previous studies. Here, we re‐investigate the Betulaceae phylogeny with whole chloroplast genomes from 24 species (17 newly assembled), representing all genera of the family. All the 24 plastomes are relatively conserved with four regions, and each genome is ∼158–161 kb long, with 111 genes. The six genera are all monophyletic in the plastome tree, whereas Ostrya Scop. is nested in the Carpinus clade in the internal transcribed spacer tree. Further incongruencies are also detected within some genera between species. Incomplete lineage sorting and/or hybrid introgression during the diversification of the family could account for such incongruencies. Our dating analysis, based on four fossils, suggests that the most recent common ancestors of the extant genera date back to the mid‐ to late Miocene, and confirms that Betulaceae started to diversify in the upper Cretaceous/early Paleocene. Our results highlight the significance of using more informative sites in resolving phylogenetic relationships. Plastome data and increased taxon sampling will help to better understand the evolutionary history of Betulaceae in the future.     

The phylogeny of Old World monkeys

The living Old World monkeys, family Cercopithecidae, are the most successful group of nonhuman primates alive today. Overall, they account for over one quarter of the extant genera of primates and approximately 40% of the species. They have an extensive fossil record extending back to the early and middle Miocene of Africa.^1,2 Despite this specific diversity and a long evolutionary history, it is commonly argued that the group is relatively uniform in both its skeletal³ and dental⁴ anatomy, suggesting that much of the current taxonomic diversity is a relatively recent phenomenon. In such a species group, it is perhaps not surprising that the taxonomy of Old World monkeys is subject to many differing classifications. Thus, in recent years, authors have recognized as few as 10 and as many as 22 different genera within the family. Although some of this greater-than-two-fold difference in the number of genera can be attributed to the “splitting” versus “lumping” philosophies of different researchers, much of it is based on major disagreements over phylogenetic relationships. Recent studies of the genetics and chromosomes of this group have illuminated Old World monkey phylogeny in many ways. Some of these studies have resolved longstanding debates based on morphological data; others have revealed phylogenetic relationships that morphologists had never suspected.     

Annotated checklist of the living sharks,batoids and chimaeras (Chondrichthyes) of the world,with a focus on biogeographical diversity

An annotated checklist of the chondrichthyan fishes (sharks, batoids and chimaeras) of the world is presented. As of 7 November 2015, the number of species totals 1188, comprising 16 orders, 61 families and 199 genera. The checklist includes nine orders, 34 families, 105 genera and 509 species of sharks; six orders, 24 families, 88 genera and 630 species of batoids (skates and rays); one order, three families, six genera and 49 species of holocephalans (chimaeras). The most speciose shark orders are the Carcharhiniformes with 284 species, followed by the Squaliformes with 119. The most species‐rich batoid orders are the Rajiformes with 285 species and the Myliobatiformes with 210. This checklist represents the first global checklist of chondrichthyans to include information on maximum size, geographic and depth distributions, as well as comments on taxonomically problematic species and recent and regularly overlooked synonymizations. Furthermore, a detailed analysis of the biogeographical diversity of the species across 10 major areas of occurrence is given, including updated figures for previously published hotspots of chondrichthyan biodiversity, providing the detailed numbers of chondrichthyan species per major area, and revealing centres of distribution for several taxa     

The diversification of the northern temperate woody flora – A case study of the Elm family (Ulmaceae) based on phylogenomic and paleobotanical evidence

Ulmaceae is a woody family widespread in northern temperate forests. Despite the ecological importance of this family, its phylogeny and biogeographic history are poorly understood. In this study, we reconstruct phylogenetic relationships within the family and infer spatio-temporal diversification patterns based on chloroplast genome (complete cpDNA) and nuclear ribosomal DNA sequences (nrDNA). The seven Ulmaceae genera are resolved in two main clades (temperate vs. tropical) by both cpDNA and nrDNA sequences. The temperate clade includes four genera, Hemiptelea, Zelkova, Planera, and Ulmus. The relationships among Planera and other genera are controversial because of inconsistent topologies between plastid and nuclear data. The tropical clade includes three genera ((Ampelocera, Phyllostylon), Holoptelea). Molecular dating and diversification analyses show that Ulmaceae originated in the Early Cretaceous (ca. 110–125 Ma) with the main lineages establishing from the Late Cretaceous to the early Eocene. The diversification rate slowed during the middle to the late Paleogene (ca. 23–45 Ma), followed by a rapid diversification of the East Asian temperate group in the Neogene, congruent with a global cooling event. The ancestral state optimization analysis suggests an East Asian origin of the temperate Ulmaceae clade during the Paleocene, which is consistent with the fossil record. Both phylogenomic and fossil evidence support East Asia as a center of origin and diversification for the temperate woody lineages.     

The fossil record of extant elasmobranchs

Sharks and their relatives (Elasmobranchii) are highly threatened with extinction due to various anthropogenic pressures. The abundant fossil record of fossil taxa has allowed the tracing of the evolutionary history of modern elasmobranchs to at least 250 MYA; nonetheless, exactly how far back the fossil record of living taxa goes has never been collectively surveyed. In this study, the authors assess the representation and extent of the fossil record of elasmobranchs currently living in our oceans by collecting their oldest records and quantifying first appearance dates at different taxonomic levels (i.e., orders, families, genera and species), ecological traits (e.g., body size, habitat and feeding mechanism) and extinction risks (i.e., threatened, not threatened and data deficient). The results of this study confirm the robust representation of higher taxonomic ranks, with all orders, most of the families and over half of the extant genera having a fossil record. Further, they reveal that 10% of the current global species diversity is represented in the geological past. Sharks are better represented and extend deeper in time than rays and skates. While the fossil record of extant genera (e.g., the six gill sharks, Hexanchus) goes as far back as c. 190 MYA, the fossil record of extant species (e.g., the sand shark, Carcharias taurus Rafinesque 1810) extends c. 66 MYA. Although no significant differences were found in the extent of the fossil record between ecological traits, it was found that the currently threatened species have a significantly older fossil record than the not threatened species. This study demonstrate that the fossil record of extant elasmobranchs extends deep into the geologic time, especially in the case of threatened sharks. As such, the elasmobranch geological history has great potential to advance the understanding of how species currently facing extinction have responded to different stressors in the past, thereby providing a deep-time perspective to conservation.     

The impact of the Pull of the Recent on extant elasmobranchs

Modern elasmobranchs have a long evolutionary history and an abundant fossil record that consists mainly of teeth. Many fossil taxa have living representatives. However, the representation of extant taxa in the fossil record is unknown. To begin to understand the geological history of extant elasmobranchs, we here assess the quality of their fossil record. We do so by assessing the Pull of the Recent (POR). The POR can bias the fossil record because the rather complete record of living taxa allows palaeontologists to identify fossil members of the modern clades and to bridge time bins where fossils are absent. We assessed the impact of the POR by quantifying the proportion of extant elasmobranchs that have a fossil record, but do not occur in the last 5 million years (Pliocene and Pleistocene). We found that the POR does not affect orders and families, but it does affect 24% of elasmobranch genera. Within the different elasmobranch orders, the Lamniformes display the most complete generic fossil record, with no impact of the POR. Although modest, the impact of the POR in extant elasmobranch genera is higher than that found in other taxa. Overall, the geological history of elasmobranchs contradicts the usual assumption that the fossil record becomes worse backwards in time. This is the case across geographical regions and tooth size, further suggesting that sampling intensity and outcrop availability might explain the POR effect on sharks and rays.     

Stereophotogrammetric analysis of occlusal morphology of extant hominoid molars: phenetics and function

Because teeth are commonly preserved in the fossil record, dental remains have often been employed in estimating evolutionary relationships among fossil hominoids. This is appropriate, however, only to the extent that dental morphology is phylogenetically informative. I have used phenetic analytic techniques to assess whether hominoid molars are likely to be useful for phylogenetic inference. Thirty-four occlusal landmarks for first and second molars were chosen; seven on each maxillary and ten on each mandibular tooth. Three-dimensional locations of these points were determined from stereophotographs of dental arcades of more than 260 specimens from six taxa (gorilla, chimpanzee, human, orangutan, siamang, and gibbon). Analytic emphasis was on canonical variates analyses of landmark coordinates for mandibular and maxillary second molars, adjusted for intergroup size differences. There is little correspondence between the systematic implications of hominoid molar morphometrics and reliable estimates of evolutionary propinquity based on interhominoid biomolecular similarities. The former seem to have been determined largely by dietary constraints. Although this suggests the possibility of using the protocol employed here to infer diets of fossil hominoids, molar crown measurements seem unlikely to serve well as phylogenetic indicators in the Hominoidea.     

Presence of sonneratiaceous pollen in middle miocene sediments, central Japan

Numerous sonneratiaceous pollen grains, found in Middle Miocene sediments of central Japan possess both meridional ridges and polar caps with inter-columellate granules Although the exine architecture of these pollen is similar to that of the living Sonneratia alba, a colpal aperture as observable in these fossil pollen grains is only rarely present in Sonneratia or in the fossil Florschuetzia, which is a form-genus showing affinity with the genus Sonneratia. The fossil pollen is described as Florschuetzia claricolpata sp.n. This new species not only has a distributional significance, but also may strengthen the phylogenetic link between the genera Florschuetzia and Sonneratia.     

Molecular phylogenetic convergence within Elasmobranchii revealed by cytochrome oxidase subunits

The phylogenetic relationships within the subclass of Elasmobranchii are under question within the academic community and their systematic classification based on morphological, or physiological characteristics has not yet been fully justified. Modern cladistic studies suggested that batoids are derived sharks, a taxonomic status known as the Hypnosqualean hypothesis. The main purpose of this study was to address this issue using a data set of aligned, directly sequenced, mitochondrial cytochrome oxidase subunits I and II. Maximum Likelihood, Maximum Parsimony, Minimum Evolution and Bayesian inference were implemented for tree reconstructions. The results provided evidence that supported the rejection of the above hypothesis, in accordance with other recent molecular phylogenetic studies. More specifically Rajiformes species were presented as separate lineages from sharks. Prionace species on the other hand was grouped within Carcharhinoformes, which was clustered as sister group to Lamniformes. COI and COII regions supported, monophylies of Squaliformes and paraphylies of Carchariniformes.     

中国长翅目昆虫化石研究现状

长翅目昆虫在地史纪录上可以追溯到早二叠纪,是全变态昆虫中最原始的种类之一.截至目前,29篇关于中国长翅目昆虫化石分类的论著发表,共描述我国长翅目昆虫化石11科28属51种,这些化石分布于从三叠纪到白垩纪的不同地层中.本文通过图表提供了我国已发现的长翅目化石名录并介绍了其分布和年代,回顾了我国长翅目昆虫化石的研究进展,指出了一些分类存在的问题,简要慨述了长翅目中一些科的起源与演化以及长翅目与其它全变态昆虫的关系.我国长翅目化石种类丰富,但在基础分类、系统演化方面还缺乏系统的研究,因而许多工作甚至最基础的分类工作亟待开展.     

Phylogeny and evolutionary history of diplobathrid crinoids (Echinodermata)

Order Diplobathrida is a major clade of camerate crinoids spanning the Ordovician–Mississippian, yet phylogenetic relationships have only been inferred for Ordovician taxa. This has hampered efforts to construct a comprehensive tree of life for crinoids and develop a classification scheme that adequately reflects diplobathrid evolutionary history. Here, I apply maximum parsimony and Bayesian phylogenetic approaches to the fossil record of diplobathrids to infer the largest tree of fossil crinoids to date, with over 100 genera included. Recovered trees provide a framework for evaluating the current classification of diplobathrids. Notably, previous suborder divisions are not supported, and superfamily divisions will require significant modification. Although numerous revisions are required for families, most can be retained through reassignment of genera. In addition, recovered trees were used to produce phylogeny‐based estimates of diplobathrid lineage diversity. By accounting for ghost lineages, phylogeny‐based richness estimates offer greater insight into diversification and extinction dynamics than traditional taxonomy‐based approaches alone and provide a detailed summary of the ~150 million‐year evolutionary history of Diplobathrida. This study constitutes a major step toward producing a phylogeny of the Crinoidea and documenting crinoid diversity dynamics. In addition, it will serve as a framework for subsequent phylogeny‐based investigations of macroevolutionary questions.     

Of teeth and trees: A fossil tip‐dating approach to infer divergence times of extinct and extant squaliform sharks

Fossil tip‐dating allows for the inclusion of morphological data in divergence time estimates based on both extant and extinct taxa. Neoselachii have a cartilaginous skeleton, which is less prone to fossilization compared to skeletons of Osteichthyans. Therefore, the majority of the neoselachian fossil record is comprised of single teeth, which fossilize more easily. Neoselachian teeth can be found in large numbers as they are continuously replaced. Tooth morphologies are of major importance on multiple taxonomic levels for identification of shark and ray taxa. Here, we review dental morphological characters of squalomorph sharks and test these for their phylogenetic signal. Subsequently, we combine DNA sequence data (concatenated exon sequences) with dental morphological characters from 85 fossil and extant taxa to simultaneously infer the phylogeny and re‐estimate divergence times using information of 61 fossil tip‐dates as well as eight node age calibrations of squalomorph sharks. Our findings show that the phylogenetic placement of fossil taxa is mostly in accordance with their previous taxonomic allocation. An exception is the phylogenetic placement of the extinct genus ?Protospinax , which remains unclear. We conclude that the high number of fossil taxa as well as the comprehensive DNA sequence data for extant taxa may compensate for the limited number of morphological characters identifiable on teeth, serving as a backbone for reliably estimating the phylogeny of both extinct and extant taxa. In general, tip‐dating mostly estimates older node ages compared to previous studies based on calibrated molecular clocks.     

Tooth development and histology patterns in lamniform sharks (Elasmobranchii,Lamniformes) revisited

The dentition of lamniforme sharks exhibits several characters that have been used extensively to resolve the phylogenetic relationships of extant taxa, yet some uncertainties remain. Also, the development of different teeth of a tooth file within the jaws of most extant lamniforms has not been documented to date. High‐resolution micro‐computed tomography is used here to re‐evaluate the importance of two dental characters within the order Lamniformes, which were considered not to be phylogenetically informative, the histotype and the number of teeth per tooth file. Additionally, the development and mineralization patterns of the teeth of the two osteodont lamniforms Lamna nasus and Alopias superciliosus were compared. We discuss the importance of these dental characters for phylogenetic interpretations to assess the quality of these characters in resolving lamniform relationships. The dental characters suggest that (1) Lamniformes are the only modern‐level sharks exhibiting the osteodont histotype, (2) the osteodont histotype in lamniform sharks is a derived state in modern‐level sharks (Elasmobranchii), (3) the osteodont type, conversely is convergently achieved when the clade Chondrichthyes is considered and thus might comprise a functional rather than a phylogenetic signal, and (4) there is an increase in the number of teeth per file throughout lamniform phylogeny. Structural development of the teeth of L. nasus and A. superciliosus is congruent with a previous investigation of the lamniform shark Carcharodon carcharias. J. Morphol. 277:1584–1598, 2016. © 2016 Wiley Periodicals, Inc.     

木灵藓科分类与系统学研究：历史、问题和展望

木灵藓科(Orthotrichaceae)是藓类植物中的第3大科。该科不仅种类多, 生态类型特殊, 而且是世界公认的多样化程度高、分类难度大、系统关系复杂的类群。当代木灵藓科植物分类系统学研究主要集中在该科的地区志编写和专属分类修订。目前, 除了热带美洲、热带非洲的变齿藓属(Zygodon)和火藓属(Schlotheimia)部分类群外, 木灵藓科主要类群的分类修订工作已基本完成, 但是有关亚科和属的划分和地位以及各属之间的关系等方面仍存在众多争议。木灵藓科分支系统学研究也不够系统全面, 有的仅应用了单个基因片段, 或者只涉及少数类群。因此, 需要基于更多的分子和形态学性状, 进一步开展世界木灵藓科植物的系统发育研究, 建立一个更趋自然的木灵藓科分类系统。