the pinhead pearlfish , carapus boraborensis , is a species of slender , ray-finned fish in the family carapidae found in the tropical indo-pacific ocean ; it normally lives inside the body cavity of a sea cucumber such as the pineapple sea cucumber ( thelenota ananas ) or the leopard sea cucumber ( bohadschia argus ) .

pinhead pearlfish

@ firstdogonmoon the cucumber or pinhead pearlfish ! superb choice . some pearlfish also eat the cucumber ' s gonads . . . strange and stranger !
kate cranney on twitter :
@ firstdogonmoon the cucumber or pinhead pearlfish ! superb choice . some pearlfish also eat the cucumber ' s gonads . . . strange and stranger !
a small reddish - brown eel - like fish covered in fine dark speckles . the pinhead pearlfish lives within holothurians , and emerges through the cloacal opening of the sea cucumber at night .
some species of this family , however , are possibly parasitic . these live inside sea cucumbers where they will first eat the gonads of their host and then live inside the anal pore . the pinhead pearlfish ( carapus boraborensis ) is suspected to be parasitic whereas the silver pearlfish ( encheliophis homei ) is suspected to be non - parasitic based on stomach content analysis and where they are found within a cucumber when dissected .
( pacific pearlfish ) is found in the eastern pacific in the body cavity of cockles , pearl shells , and pen shells .
( bivalve pearlfish ) occurs in marine waters off western australia . it prefers to reside within sea cucumbers and the mantle cavity of bivalves
parmentier , e . and vandewalle , p . ( 2003 ) morphological adaptations of pearlfish ( carapidae ) to their various habitats . science publisher
before entry , a pearlfish will normally spend several minutes inspecting the entire body length of a cucumber before proceeding to the back end . a knocking or tapping movement is performed near the anus as if
asking
to gain entry . reports indicate that pearlfish normally back in tail first but have also been observed to enter head first . more than one pearlfish has been known to live inside a cucumber at any one time as well making for a somewhat cramped living environment . this trait has been observed with the silver pearlfish where sexual pairing has been found within a cucumber .
the great pearlfish , conqueror of sea cucumber bums , devourer of reproductive organs , all - around decent critter to anything but a sea cucumber .
( pearlfish ) is found in the western pacific on reefs . this fish lives in the body cavity of sea cucumbers by day and forages at night
this bizarre little fish lives inside the anus of a leopard sea cucumber ( bohadschia argus ) . i was filming a number of different fishes in the shallows , and only took a short clip of this sea cucumber . it wasn ' t until i looked at the footing that i saw the little pearlfish . pearlfish get their name from the members of their family that live inside oysters .
but the sea cucumber may not be entirely defenseless against the invasions of the pearlfish . some species have what could be functioning as a built - in gate in their anus — a handy accessory considering that in addition to the pearlfish , crabs and clams have also been known to make themselves at home inside the poor critters ( the sea cucumber , it seems , like any good host , can never really enjoy itself at its own party ) .
depending on what species it is , the pearlfish initiates one of two relationships once inside : a commensal one , in which it simply takes up space without either helping or adversely affecting the sea cucumber , or a rather more parasitic one , in which it chows down on its host’s gonads .
the pearlfish finds its reluctant host likely by smell , according to biologist eric parmentier of belgium’s university of liège . it then must choose the right end to enter , using its lateral line — sensory organs that detect movements in water — to home in on the outflow from the respiratory tree at the anus .
such pearlfishes come in a range of species , and don’t necessarily limit themselves to invading sea cucumbers . they’ll also work their way into sea stars , and are so named because they’ve been found dead inside oysters , completely coated in mother - of - pearl . beautiful , really , though i reckon the pearlfish would beg to differ .
pearlfish ( family carapidae ) are scaleless , their bodies are somewhat translucent , and they look remotely like eels when they swim outside of their host . they can be found in the atlantic , pacific and indian oceans and have been found down to depths of over 2 , 000 meters . some of the species can reach upwards of 50 cm in length when full grown .
ophidiiformes represent the
cusk eels
and some species within the family carapidae ( pearlfish ) live symbiotically within benthic invertebrates . the relationship of the fish to the host is quasi - parasitic ; only in a few cases is the parasitism overt . in most cases , the fish either consumes food that could be used by the host or , in most cases , simply takes up space
you’re breathing through your anus , by the way , and when you take a breath , the pearlfish strikes — squirming up your butt , making itself comfortable in your respiratory organ , and eating your gonads . or , they’ll go up in pairs and have sex in your body cavity . and that’s when you realize that you must have been a really awful human being in a past life . like , the type of person who talks on their phone in a movie theater kind of awful .
so like a disgraced samurai disemboweling himself , the sea cucumber gifts the world with its intestines , whether the world wants them or not . interestingly , though , the pearlfish doesn’t itself seem to trigger this reaction for reasons that aren’t yet clear . and it’s important to consider that the fish in fact benefits from the evisceration , because by using the sea cucumber as a home , it necessarily adopts its host’s predators . its survival depends on the sea cucumber’s ability to defend itself , which is quite intriguing from an evolutionary perspective .
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eel - like , moderate to shallow body depth ; maxilla free and movable ; cardiform teeth present ; branchiostegal membranes partly or completely united ; swim bladder with thin terminal membrane or bulb but no constriction ; lacking enlarged dentary or premaxillary fangs , dentary diastema , pelvic fins , and swim bladder rocker bone ; pectoral fins small , less than 29 % head length ; body thick , robust and highly pigmented ; 15 - 17 precaudal vertebrae .
uncommon species . shallows water of coral reefs . lives within holothurians ( e . g . thelenota ananas < \ i > , bohadschia argus < \ i > and stichopus chloronotus < \ i > ) .
indo - pacific : mauritius to the society islands , north to taiwan and the yaeyama islands ; including mariana and caroline islands .
greek , enchelys , = eel + greek , ophis = serpent ( ref . 45335 )
marine ; demersal ; depth range 1 - 150 m ( ref . 34024 ) . tropical
maturity : l m ? range ? - ? cm max length : 30 . 0 cm tl male / unsexed ; ( ref . 4104 )
dorsal soft rays ( total ) : 31 - 42 ; anal soft rays : 45 - 57 ; vertebrae : 119 - 126 . eel - like , moderate to shallow body depth ; maxilla free and movable ; cardiform teeth present ; branchiostegal membranes partly or completely united ; swim bladder with thin terminal membrane or bulb ; lacking enlarged dentary or premaxillary fangs , dentary diastema , pelvic fins , and swim bladder rocker bone ( ref . 34024 ) . pectoral fins small , less than 29 % head length ; body thick , robust and highly pigmented ( ref . 34024 ) .
uncommon species ( ref . 34024 ) . lives within holothurians ( e . g . thelenota ananas and bohadschia argus ) ( ref . 1602 ) .
nielsen , j . g . , d . m . cohen , d . f . markle and c . r . robins , 1999 . ophidiiform fishes of the world ( order ophidiiformes ) . an annotated and illustrated catalogue of pearlfishes , cusk - eels , brotulas and other ophidiiform fishes known to date . fao fish . synop . 125 ( 18 ) : 178p . rome : fao . ( ref . 34024 )
) : 23 . 6 - 28 . 9 , mean 27 . 5 ( based on 920 cells ) . phylogenetic diversity index ( ref .
bayesian length - weight : a = 0 . 00102 ( 0 . 00046 - 0 . 00225 ) , b = 3 . 06 ( 2 . 88 - 3 . 24 ) , in cm total length , based on all lwr estimates for this body shape ( ref .
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picture of carapus boraborensis has been licensed under a creative commons attribution - noncommercial . original source : fishbase permission : some rights reserved
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project noah is a tool to explore and document wildlife and a platform to harness the power of citizen scientists everywhere .
lady elliot island ' s shallow coral lagoon , in the coral sea at the south end of the great barrier reef .
i know . it lives in a sea cucumber bottom ! from what i ' ve read the sea cucumber is not getting anything out of the
relationship
. nature , weirder than anything we can imagine . the video i put up at youtube is a too cropped . i ' ll see if i can fix that so you can see the fish better .
marine ; demersal ; depth range 1 - 150 m ( ref . 34024 ) . tropical , preferred ?
confused by a class within a class or an order within an order ? please see our brief essay .
to cite this page : myers , p . , r . espinosa , c . s . parr , t . jones , g . s . hammond , and t . a . dewey . 2018 . the animal diversity web ( online ) . accessed at https : / / animaldiversity . org .
disclaimer : the animal diversity web is an educational resource written largely by and for college students . adw doesn ' t cover all species in the world , nor does it include all the latest scientific information about organisms we describe . though we edit our accounts for accuracy , we cannot guarantee all information in those accounts . while adw staff and contributors provide references to books and websites that we believe are reputable , we cannot necessarily endorse the contents of references beyond our control .
this material is based upon work supported by the national science foundation grants drl 0089283 , drl 0628151 , due 0633095 , drl 0918590 , and due 1122742 . additional support has come from the marisla foundation , um college of literature , science , and the arts , museum of zoology , and information and technology services .
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these fish are unique in that the adults normally live inside invertebrates like clams , sea squirts , and starfish in a commensal relationship ( not harming their host ) . this trait is common throughout the carapidae family .
this pairing behavior is not often seen in our reef aquariums but occasionally members of various reefkeeping forums will report that they have one in their tank .
watch the video below to see this relationship . if you ' re short on time , skip ahead to the 6 minute mark for the re - entry . . .
shane has kept saltwater tanks for the last 12 years , is a research scientist , lives in northern indiana , and is a proud advanced aquarist staffer .
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) : 23 . 6 - 28 . 9 , mean 27 . 5 ( based on 920 cells ) .
phylogenetic diversity index ( ref . 82805 ) : pd 50 = 0 . 5078 [ uniqueness , from 0 . 5 = low to 2 . 0 = high ] .
bayesian length - weight : a = 0 . 00102 ( 0 . 00046 - 0 . 00225 ) , b = 3 . 06 ( 2 . 88 - 3 . 24 ) , in cm total length , based on all lwr estimates for this body shape ( ref . 93245 ) .
trophic level ( ref . 69278 ) : 3 . 4 ±0 . 3 se ; based on size and trophs of closest relatives
vulnerability ( ref . 59153 ) : low vulnerability ( 16 of 100 ) .
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conceived and designed the experiments : oh fl . performed the experiments : oh . analyzed the data : oh fl . contributed reagents / materials / analysis tools : fl . wrote the paper : oh fl . obtained permission for animal experiments : fl .
this is an open - access article distributed under the terms of the creative commons attribution license , which permits unrestricted use , distribution , and reproduction in any medium , provided the original author and source are properly credited .
data on sex - specific differences in sound production , acoustic behaviour and hearing abilities in fishes are rare . representatives of numerous catfish families are known to produce sounds in agonistic contexts ( intraspecific aggression and interspecific disturbance situations ) using their pectoral fins . the present study investigates differences in agonistic behaviour , sound production and hearing abilities in males and females of a callichthyid catfish .
current data demonstrate that both male and female m . thoracata produce aggressive sounds , but the behavioural contexts and sound characteristics differ between sexes . sexes do not differ in hearing , but it remains to be clarified if this is a general pattern among fish . this is the first study to describe sex - specific differences in agonistic behaviour in fishes .
a wealth of information is available on sound - generating mechanisms , sound production during agonistic and reproductive behaviour , and hearing in fishes ( for reviews see [ 1 – 5 ] ) . despite this knowledge , data on sex - specific differences in sonic organs , sound production and in hearing are very limited [ 6 ] .
a previous study on the callichthyid armoured catfish megalechis thoracata ( formerly hoplosternum thoracatum ) showed that , corresponding to the behavioural contexts , males and females uttered different types of pectoral sounds [ 27 ] . this differs considerably from investigations on the callichthyid c . paleatus , in which males produced trains of sounds during dyadic contests , whereas no stridulation sounds could be recorded from females during social interactions [ 13 , 28 ] .
acoustic communication is defined as transmission of information by a sender to a receiver with benefits for the receiver or mutual potential benefits for both [ 36 ] . accordingly , a match of spectral contents of sounds and best hearing sensitivity of the intended receiver , and vice versa , should be preferred by natural selection [ 33 , 35 ] . auditory sensitivity was found to match the characteristics of sounds produced in the frequency domain in some species [ 35 , 37 – 41 ] , but mismatch was observed in others [ 33 , 42 ] .
the aims of the present study were to investigate sex - specific differences in ( 1 ) sound - generating mechanisms , ( 2 ) agonistic behaviour , ( 3 ) sounds produced and their characteristics , ( 4 ) the auditory abilities , and finally ( 5 ) to determine if the dominant frequencies of sounds correlate with the best hearing sensitivity in the callichthyid catfish m . thoracata .
experiments were performed with permission of the austrian federal ministry of science and research ( bundesministerium für wissenschaft und forschung , gz 66 . 006 / 0023 - ii / 10b / 2008 ) . the permission covered all experimental procedures . no animal was sacrificed during this study . according to the austrian law on experiments in animals ( tierversuchsgesetz 1989 / 2005 ) an institutional animal care and use committee ( or ethics committee ) was not mandatory and did not exist at the university of vienna when experiments were carried out .
seventeen specimens of m . thoracata were used for the study : seven subadult males ( 93–104 mm total length , tl , 12 . 2–19 . 1 g body mass ) , nine subadult females ( 84–102 mm , 9 . 8–17 . 1 g ) and one adult male ( 126 mm , 32 . 9 g ) . fish were obtained from a local pet shop and a fish farmer . we assume that 16 of the 17 fish were subadult because they were one year old during our experiments and mayr [ 27 ] stated that first reproductive behaviour in this species is shown at the age of two years . moreover , we observed no reproductive behaviour in the present study when sexes were kept together in community tanks . this species is a bottom - dwelling fish from slowly flowing rivers , pools , drainage ditches and swampy areas in south america [ 43 ] .
the sex of the fish was determined by inspecting the genital papillae , the distance between coracoids and the size of pectoral fins . males possess genital papillae , a narrower gap between coracoids and longer , thicker and orange pectoral spines [ 43 ] . due to the individually spotted body pattern , the subjects could be easily distinguished from each other .
fish were kept in three community tanks ( 110 x 30 x 55 cm ) whose bottom was covered with fine sand and which were similarly equipped with half flower pots , tubes , plants and roots as shelters . the tank of the adult male measured 90 x 30 x 30 cm . four males and four females and three males and five females , respectively , were kept together . a 12 : 12 hour light : dark cycle was provided and the water temperature was kept at 25 ± 1°c . the aquaria were filtered by external filters in order to reduce noise . fish were fed frozen chironomid larvae and occasionally artificial food ( flakes and tablets ) five to six times a week .
after behaviour and sound recordings , body mass , total length and length of the pectoral spine of each contestant were measured . the pectoral spine length ( psl ) was measured from the juncture of the spine with the outer body surface to its tip using digital callipers . the relative pectoral spine length ( rpsl ) was calculated using the formula rpsl = psl / tl , where tl is the total length .
all agonistic experiments were performed from august to november 2011 . fish were kept for three months in holding tanks before the start of behavioural experiments . the video and sound recordings were carried out in a walk - in soundproof room , which was constructed as a faraday cage . the experiments were conducted in a test tank ( 70 x 40 x 35 cm ) . the resonant frequency of the tank is 3042 hz according to akamatsu et al . [ 44 ] . the water temperature was maintained at 25 ± 1°c . the test tank was placed on a table that rested on a vibration - isolated concrete plate .
the behaviour and acoustic signals were recorded using a hydrophone ( brüel & kjaer 8101 , sensitivity −184 db re 1 v μpa −1 ) , which was connected to a power supply ( brüel & kjaer 2804 ) and placed in the centre of the aquarium close to the back wall . both the hydrophone and video camera ( sony ccd - vx1e ) were connected to a hifi s - vhs video cassette recorder ( jvc hr - s4700 eg / e ) . hifi audio and s - video signals were stored simultaneously on s - vhs hifi videotapes ( fujifilm super vhs pro se - 240 ) . sound pressure levels ( rms fast time weighting , linear frequency weighting ) were measured in parallel with the sound recordings using a sound level meter ( brüel & kjaer mediator 2238 ) connected to the power supply . the observer was always hidden behind a curtain during recordings . external filters of the test tank were switched off before the start of experiments .
as the intention of this study was to record acoustic displays during agonistic behaviour dyadic interactions were not allowed to proceed to a phase , where biting might have occurred . no biting or injuries were observed in any of the experiments .
each sound was digitized using a sampling rate of 11 khz ( 16 bit resolution ) and analysed using cool edit 2000 ( syntrillium software corporation , phoenix , usa ) and st x soundtools 3 . 7 . 8 . ( institute of sound research at the austrian academy of sciences , vienna ) . only sounds with a good signal - to - noise ratio were analysed . the following acoustic variables were measured from sounds recorded during dyadic contests :
sound duration ( sd ) : the total length between the onset and the end of a single call or a series of sounds . dominant frequency ( df ) : the frequency with the highest amplitude within a power spectrum . the dominant frequency of sounds was determined from cepstrum - smoothed power spectra . harmonic sounds are characterized by several regularly spaced peaks , in which the frequencies of the harmonic peaks are multiples of that of the fundamental frequency . the harmonic content of a sound was controlled by overlaying a harmonic grid .
sound pressure level ( spl ) : measured in db re 1μpa ( rms fast , linear weighting ) . in order to compensate the varying distances of vocalizing fish to the hydrophone , a correction factor was calculated . therefore , the test tank was divided into 21 sectors ( each measuring 10 x 10 cm ) by using a grid applied on the front glass of the aquarium . the sector in which a fish emitted sounds was noted . because sounds of m . thoracata were of low energy , pink noise was chosen for calculating a correction factor . short tone bursts were played back at a constant spl from a small loudspeaker ( fuji 7g06 , 8 ohm , 0 . 8 w ) , in each of the 21 sectors , and the spls were noted . the relative difference of the spl measured in the sector nearest to the hydrophone ( 3 cm away ) and the other sectors were calculated and added to the spl values of fish sounds measured before . thus , a distance - independent absolute spl value could be determined for each sound emission .
the aim of the behavioural analyses was to describe all behavioural patterns ( elements ) occurring during the male - male and female - female agonistic contests . all behavioural patterns shown during a total of 24 agonistic encounters were classified according to the description presented in
. the number of acoustic signals and visual displays such as attack , circling and head nodding was counted for each experiment and individual .
description of the behavioural repertoire shown during dyadic male - male and female - female interactions of m . thoracata .
fin displaying or approaching another fish , stopping suddenly before forcefully hitting the other with its tail .
two females swam in an anti - parallel ( head - to - tail ) orientation .
two males moved towards each other , in a parallel , anti - parallel position or various angles spreading all their fins . additionally , at high intensities the caudal part of the body was erected in a distinct angle .
continued escape reaction in response to a chase . fish swam rapidly away from the aggressor .
females showed serial vertical up and down movements of their heads in different positions to each other .
males moved their heads rapidly away and towards the opponent while bending their body c - like .
one female following the opponent by a snake - like movement on the bottom .
definitions followed mayr [ 27 ] except for fin beating , jerks and sneaking . m—males , f—females .
auditory sensitivity was determined using the non - invasive auditory evoked potential ( aep ) recording technique , originally reported by kenyon et al . [ 45 ] and modified by wysocki and ladich [ 46 – 47 ] .
for each test condition , the stimuli were presented at opposite polarities ( 180° phase shifted ) and the corresponding aeps were averaged in order to eliminate stimulus artefacts . at spls close to the threshold , this procedure was performed at least twice and the aep traces were overlaid to examine if they were repeatable . the spl values of tone burst stimuli were reduced in 4 db steps . by overlaying replicate traces , the lowest spl in which an identifiable and repeatable aep trace could be obtained was regarded as threshold . the method developed by kenyon et al . [ 45 ] gives auditory thresholds very similar to behavioural thresholds ( for discussion see [ 4 , 48 ] ) .
additionally , a one - way analysis of variance ( anova ) was performed , followed by a bonferroni post - hoc test , in order to determine differences in sound characteristics of each aggressive sound type . differences in relative pectoral spine length between sexes were tested using a paired t - test . a total of 244 sounds were analysed .
mean hearing thresholds were determined for both sexes at each frequency . thresholds obtained for males ( n = 6 ) and females ( n = 6 ) were compared by a two - way anova using a general linear model , where one factor was sex and the other was frequency . the sex factor alone should reveal differences in sensitivity between sexes and , combined with the frequency factor , if different tendencies exist at different frequencies of the audiograms .
all statistical tests were conducted using pasw 18 . 0 ( spss inc . , chicago , usa ) . the significance level was set at p ≤ 0 . 05 .
produced sounds by vibrating pectoral fins . the first pectoral fin rays were orange in males in contrast to females . pectoral spines were longer and thicker in males . the relative length of pectoral spines ( pectoral spine length / total length ) was on overage 1 . 7 - fold higher in males than females ( t - test , t = 44 . 27 , df = 15 , p ≤ 0 . 01 ) (
different letters indicate statistically significant differences between sexes . psl—total length of pectoral spine , tl—total fish length .
aggressive interactions usually started after removal of the separating sheet and as soon as opponents detected each other visually . the agonistic behavioural sequences were interrupted by air gulping , digging , resting close to each other or withdrawal into the shelter . for the description of behavioural patterns observed during thirteen male - male and eleven female - female encounters see
generally , one or both males started to approach each other and erected their fins ( threatening fin display ) . occasionally , this posture was followed by fin beating , which could last for several seconds . head jerking followed and was accompanied by the production of two sound types , namely barks or thumps , indicating high levels of aggression . jerking could occur without sound emission , in which case maximally three jerks were observed .
in 12 out of 13 encounters ( 92 % ) , barks and thumps were produced during aggressive interactions . furthermore , in 10 out of 13 contests ( 78 % ) , sound emission occurred in both contestants . barks were emitted at various distances from a few centimetres up to a maximum of 40 cm away from the opponent . before abduction of pectoral fins , a single adduction was observed . barks were often produced during approaching and swimming (
) . the individual producing a sound mostly swam away and then again approached the conspecific . the latter could react by fin displays or moving away from the other .
the illustration shows the right male approaching the opponent , shortly before uttering a bark .
in contrast to barks , thumps occurred only in direct proximity ( within one body length ) to the opponent . typically , opponents showed fin displays in a parallel , anti - parallel position or at various angles to each other (
) , or swam close and emitted thumps . typically , thumps were produced in an oblique position towards the opponent . opponents responded by producing a thump , by attacking or by fleeing .
this screen shot shows the typically threatening fin display with fins spread and the caudal part of the right male erected in a distinct angle . the right fish produced a thump in this oblique anti - parallel position relative to the conspecific .
during all experiments , we counted a total of 40 attacks , often preceded by fin display and fin beating . attacks were mainly performed by sound producers , occasionally accompanied by thumps . besides these behavioural elements , chasing was observed . during chasing , barks were emitted by the pursuer .
in five out of seven experiments , barks were even emitted after separating both fishes by the plastic sheet , i . e . after they lost visual contact . barks were recorded mainly in males , which produced numerous sounds during the dyadic contests . just in one case did both opponents emit barks . after separation by the plastic sheet , males generated barks during swimming or when approaching the separating sheet .
) close to the bottom . this sneaking behaviour toward the opponent was occasionally accompanied by the emission of crackles . sounds were recorded in all female - female experiments . in four out of eleven contests , both females vocalized during agonistic interactions . sounds were produced close to the opponent ( within one to two body lengths ) (
) and were generated by rapid pectoral fin movements . shortly before uttering a crackle , the vocalizing fish may strike towards the opponent . crackles were most frequently emitted when one female chased the other . swimming after each other or pursuing could continue into circling behaviour (
) , which lasted up to 3 s . sounds were uttered before , during or at the end of circling .
head nodding was either performed by one female or simultaneously by both . two to 18 head nods per individual were observed within a series . we counted a total of 736 head nods during eleven agonistic interactions , and the vocalizing female exhibited a higher rate . this visual threatening display could be elicited by the movement of one fish , when swimming by or when above the other , before and after circling , and when resting close to each other . furthermore , interactions were characterized by a high rate of body contacts such as touching with barbels . attacks occurred only four times : three were accompanied by crackles and one was exhibited shortly after head nodding .
in contrast to male - male encounters , in which both males vocalized , crackles were mainly produced by one female , seldom by both . female - female contests were characterized by circling behaviour and the lack of jerks . head nodding could not be observed in any male - male interaction . while males beat their fins during fin displays , females did it during circling . females undulated only their dorsal and caudal fins , whereas in males all fins were involved . furthermore , females attacked less frequently than males , indicating a lower level of aggressivity .
three types of sounds were recorded during dyadic encounters . males produced barks and thumps , and females emitted crackles . barks and thumps were recorded in seven out of eight males and crackles in eight out of nine females . the fish produced 376 barks , 66 thumps and 739 crackles during 24 interactions . acoustic signals were not audible to human listeners . video analysis revealed that barks were produced during abduction of the pectoral fin . we could not unequivocally determine the movement of the pectoral fins ( adduction and / or abduction ) during the emission of thumps and crackles .
barks were low - frequency harmonic sounds showing frequency modulation ; they only occurred singly . they consisted of one to three parts and were therefore classified as being mono - , bi - or tripartite (
) . sound duration ranged from 159 to 317 ms , and the spl ranged from 101 . 2 to 125 db re 1 μpa at a distance of 3 cm . the main energies were found in the first , second or third harmonic . the dominant frequency of bipartite barks varied in the first part from 110 to 600 hz , and in the second from 170 to 730 hz .
the spectrum shows three harmonics ( 1st , 2nd , 3rd ) with the highest energy found in the second harmonic . sampling rate 22 khz . hanning filter , overlap 75 % , ( a ) filter bandwidth 20 hz , ( b ) filter bandwidth 1 hz , number of coefficients 350 .
the spectrum reveals three harmonics ( 1st , 2nd , 3rd ) within the second sound part ( white arrow ) with the highest energy found in the second harmonic . the oscillogram shows lower amplitude in the first part ( light blue arrow ) . sampling rate 11 khz . hanning filter , overlap 75 % , ( a ) filter bandwidth 20 hz , ( b ) filter bandwidth 1 hz , number of coefficients 170 .
thumps were produced singly and showed no harmonic structure . they were mostly mono - , seldom bipartite (
) . bipartite thumps were recorded only in the one examined adult subject . sound duration ranged from 116 to 446 ms and the spl ranged from 107 . 07 to 137 . 5 db re 1 μpa . the dominant frequency varied from 70 to 210 hz .
the dominant frequency is indicated in ( b ) . sampling rate 11 khz . hanning filter , overlap 75 % , ( a ) filter bandwidth 20 hz , ( b ) filter bandwidth 1 hz , number of coefficients 80 .
female crackles differed from male sounds in their complex structure and frequency content . they were of higher frequency and always consisted of series of sound elements (
) . crackles were built up mostly by four sound elements ( range : 2–8 elements ) . these series were characterized by a main element featuring the highest peak - to - peak - amplitude and several elements of lower amplitude before and after the main element (
) . elements could be separated by intervals from each other and could consist of a substructure such as a train of pulses ( = one element ) .
the oscillogram shows five sound elements . the white arrow indicates the main element , followed by a train of pulses . the dominant frequency is indicated in the cepstrum - smoothed power spectrum in ( b ) . sampling rate 11 khz . hanning filter , overlap 75 % , ( a ) filter bandwidth 100 hz , ( b ) filter bandwidth 1 hz , number of coefficients 20 .
the duration of crackles ranged from 81 to 394 ms . single elements ( including train of pulses ) ranged from 5 . 6 up to 192 . 9 ms and main elements varied from 15 . 3 to 57 . 6 ms in duration . spls were between 101 . 5 and 128 . 1 db re 1 μpa . dominant frequencies of crackles varied from 370 to 830 hz .
) . thumps were significantly louder than barks and crackles , but no such difference was found between barks and crackles ( bonferroni post - hoc test ) . furthermore , the dominant frequencies varied between sound types ( one - way anova : f
) . mean dominant frequencies of crackles were much higher than of other sound types . the first part of barks and thumps did not differ significantly in dominant frequency ( bonferroni post - hoc test ) .
mean ( + se ) sound duration of male barks and thumps ( n = 7 ) and of female crackles ( n = 8 ) .
mean ( + se ) sound pressure level of male barks and thumps ( n = 7 ) and of female crackles ( n = 8 ) .
mean ( + se ) dominant frequency of male barks and thumps ( n = 7 ) and of female crackles ( n = 8 ) .
sound characteristics of male barks and thumps and female crackles were significantly correlated to morphological measures when males and females were pooled . duration of male thumps and female crackles combined increased with mean total length and pectoral spine length (
correlations between mean sound characteristics ( sound duration , dominant frequency , sound pressure level ) of male and female sound types and morphological variables ( total length , pectoral spine length , relative pectoral spine length ) .
n = 15 . b—bark , bp—bark part , c—crackles , t—thumps . pearson’s correlation coefficients are given . asterisks indicate statistically significant differences .
) . individuals with larger pectoral spines emitted sounds of lower frequency . mean dominant frequencies of the first part of barks ( or the second part of barks ) , or of thumps and females crackles combined , were negatively correlated to pectoral spine lengths (
thus , mean sound characteristics were always correlated to relative pectoral spine lengths , except for spls of male barks . in contrast , only sound duration and spls of thumps and crackles combined were correlated to total length (
all fish detected tone bursts between 100 hz and 4 khz . hearing curves of both sexes were u - shaped with best auditory sensitivities between 0 . 2 and 1 khz (
) . hearing abilities decreased rapidly above 1 khz . thresholds increased by 41 db between 1 and 4 khz in males and females . overall , hearing thresholds did not differ between sexes ( two - way anova : f
= 1 . 2 , n . s . ) . females had better hearing between 0 . 1 and 1 khz ( two - way anova : f
= 0 . 007 , n . s . ) . no significant interaction was found between sex and frequency . thus , the difference in auditory sensitivity between 0 . 1 and 1 khz was not frequency - dependent .
mean ( ± se ) auditory sensitivities of male ( n = 6 ) and female ( n = 6 ) m . thoracata .
) . the greatest energy of sounds was concentrated from 180 to 620 hz in male barks , from 100 to 540 hz in male thumps and from 470 to 750 hz in female crackles . main energies of male and female sounds were much lower than the resonant frequency of the test tank ( see energy peak at 3 khz in
( solid lines ) in relation to spectral characteristics of sounds ( dotted lines ) .
power spectra of sounds were averaged of sounds of all individuals and are shown in relative amplitude values ( right y - axis ) .
video analysis revealed that both sexes of m . thoracata produced sounds during rapid pectoral fin movements . therefore , we assume that sound production is based on a stridulatory mechanism , well known in numerous catfish families [ 50 ] . while we observed that male barks were produced during abduction of pectoral fins , the movement of pectoral spines during generation of thumps and crackles remains unclear due to faster movements of fins and technical limitations of a standard video recording system . pruzsinszky and ladich [ 13 ] mentioned that c . paleatus produced sounds by abducting the pectoral fins alternately . similarly , heyd and pfeiffer [ 51 ] reported that in the callichthyid catfish d . urostriatum sounds were produced during abduction , and all members of the family callichthyidae probably generate sounds during abduction of pectoral fins . we assume that barks and thumps are generated by a single pectoral fin abduction and crackles by several fin abductions depending on the number of elements within a crackle sound .
the current study revealed that agonistic behaviour of male and female m . thoracata differed from each other . male agonistic behaviour mainly consisted of fin displays and jerks , whereas female behaviour was characterized by circling , head nodding , sneaking and striking . agonistic sounds were produced by males and females in different behavioural contexts . while males uttered thumps during threatening displays and barks mostly during approaching and swimming , females , in contrast , emitted crackles mainly during chasing behaviour . threatening displays in males consisted of a sequence of visual displays shown by both opponents , during which both may produce sounds . in contrast , chasing behaviour in females was typically shown in one individual , which vocalized when following or moving toward the other fish .
based on the present data , male m . thoracata seem to be more aggressive than females as revealed by the much higher number of attacks ( 40 in males versus four in females ) observed during a similar number of same - sex contests . the vocalizing behaviour of m . thoracata differs markedly from the closely related callichthyine subfamily member c . paleatus , in which only males produced trains of sounds during courtship and in which aggressive behaviour was absent during dyadic contests [ 13 ] . kaatz and lobel [ 56 ] mentioned that male corydoras spp . emitted agonistic chase sound only before , during and after spawning . this difference between the genera corydoras and megalechis is primarily due to their different mating systems . male megalechis are territorial and defend nest sites , while male corydoras do not build nests or show parental care .
the observation that fin beating and sound production occurred at short distances to the opponent indicates that water movement may be detected by the lateral line . this may constitute a third communication channel besides the visual and acoustic ones . such hydrodynamic cues are potentially involved in all short - distance agonistic and reproductive activities in fishes but seldom unequivocally proven . satou et al . [ 58 ] showed that visual and vibrational ( lateral line detected ) stimuli elicit spawning behaviour in male red salmon oncorhynchus nerka .
our study revealed three different agonistic sound types ( two in males , one in females ) based on physical characteristics of sounds . mean sound duration in m . thoracata differed between sexes , with female crackles ( 167 ms ) being shorter than both male barks ( 219 ms ) and thumps ( 240 ms ) . mean spls of thumps ( 123 db ) were higher than those of barks ( 112 db ) and crackles ( 115 db ) . mean dominant frequency of female crackles ( 562 hz ) was much higher than that of male sounds ( 132–403 hz ) . in contrast , mayr [ 27 ] wrote that aggressive signals ( = thumps ) were shorter than territorial sounds ( = barks ) . nonetheless , there is a lack of information about whether male sounds differ from female sounds because the sound characteristics have not been compared statistically between sexes . differences between the current and the prior study by mayr [ 27 ] may reflect that the present study investigated subadult fish and the former only adult reproductive fish . our fish were most likely immature because we observed no reproductive behaviour in community tanks .
) . all show best sensitivity between 0 . 3 and 1 khz and a step decrease in sensitivity above 1 khz [
] showed that smaller swimbladders and fewer weberian ossicles results in a decrease in sensitivity above 1 kilohertz .
aep - audiograms of all representatives of the family callichthyidae investigated in the recent and in prior studies .
megalechis thoracata ( current study , females and males pooled ) , corydoras paleatus [ 33 ] , corydoras sodalis and dianema urostriatum [ 52 ] .
in summary , this is the first investigation showing sex - specific differences in agonistic behaviour , sound production , sound characteristics and hearing abilities using same - sex agonistic contests . the data reveal clear differences in agonistic behaviour , which have not been shown in any fish species before . this study furthermore indicates that differences in sound characteristics between sexes seem to be due to the dimorphism in the pectoral sonic organs in megalechis .
we want to thank tanja schulz - mirbach , walter lechner , jessica jaxion - harm , angelika zebedin , isabelle maiditsch and jasmin oswald for their help with sound level measurements , isabelle maiditsch for her advice regarding analysis of female sounds and hearing measurements , and sonja windhager for her introduction to camstudio . finally , we want to thanks michael stachowitsch for scientific english proofreading and a reviewer for its helpful comments .
this article was supported by the open access publishing fund of the university of vienna . the funders had no role in study design , data collection and analysis , decision to publish , or preparation of the manuscript .
data will be uploaded in our university’s repository as soon as the paper has been accepted .
amorim mcp . diversity in sound production in fish in : ladich f , collin sp , moller p , kapoor bg , editors .
ladich f , fine ml . sound - generating mechanisms in fishes : a unique diversity in vertebrates in : ladich f , collin sp , moller p , kapoor bg , editors .
ladich f , myrberg aa . agonistic behaviour and acoustic communication in : ladich f , collin sp , moller p , kapoor bg , editors .
myrberg aa , lugli m . reproductive behavior and acoustical interactions in : ladich f , collin sp , moller p , kapoor bg , editors .
ladich f . acoustic signaling in female fish in : ladich f , editor .
variation with fish length , sex , stage of sexual maturity , and season in the appearance and volume of the drumming muscle of the swim - bladder in the haddock , melanogrammus aeglefinus ( l . )
studies on the underwater sound . 7 . underwater calls of the japanese drum fishes ( sciaenidae )
hill gl , fine hl , musick ja . ontogeny of the sexually dimorphic sonic muscle in three sciaenid species . copeia . 1987 ; 708–713 .
ueng j - p , huang b - q , mok h - k .
kéver l , boyle ks , dragičević b , dulčić j , casadevall m , parmentier e .
sound production and associated behavior in a cichlid fish , cichlasoma centrarchus . ii breeding pairs
sound production by the river bullhead cottus gobio l . ( cottidae , teleostei )
simoes jm , duarte ig , fonseca pj , turner gf , amorim mc .
oliveira tpr , ladich f , abed - navandi d , souto as , rosa il .
mayr m . verhaltensbeobachtungen an hoplosternum thoracatum , cuvier & valenciennes ( 1840 ) , mit besonderer berücksichtigung des lautverhaltens . doctoral thesis , university of vienna . 1987 .
ladich f , popper an . parallel evolution in fish hearing organs in : manley g , fay rr , popper an , editors .
ladich f . diversity in hearing in fishes : ecoacoustical , communicative , and developmental constraints in : koeppl c , manley g . a . , popper a . n . , fay r . r . , editors .
. new york : springer science + business media ; 2014 . pp 289–321 .
fine ml . mismatch between sound production and hearing in the oyster toadfish in : tavolga wn , popper an , fay rr , editors .
. neptune city , nj : t . f . h . publications ; 1998 .
fine ml , ladich f . sound production , spine locking and related adaptations in : kapoor bg , arratia g , chardon m , diogo r , editors .
enfield , nh : science publishers , inc ; 2003 . pp . 249–290 .


holoptychius is an extinct genus of porolepiform lobe-finned fish from the middle devonian to carboniferous ( mississippian ) periods .

it is known from fossils worldwide .

the genus was first described by louis agassiz in 1839 .

holoptychius

holoptychius bergmanni sp . nov . ( sarcopterygii , porolepiformes ) from the upper devonian of nunavut , canada , and a review of holoptychius taxonomy
title : the porolepiform holoptychius jarviki author : illustration by philippe janvier sources : parc national de miguasha year : 2002 description : the porolepiform holoptychius jarviki , as drawn by philippe janvier .
holoptychius cf . nobilissimus agassiz : lukševičs & zupinš , 2004 , lk . 108 , joon .
title : reconstruction of the porolepiform holoptychius jarviki author : illustration by françois miville - deschênes sources : parc national de miguasha year : 2000 description : reconstruction of the porolepiform holoptychius jarviki found at miguasha .
what made you want to look up holoptychius ? please tell us where you read or heard it ( including the quote , if possible ) .
title : holoptychius jarviki author : parc national de miguasha sources : parc national de miguasha year : 2002 description : the type specimen of the porolepiform holoptychius jarviki was discovered at miguasha by the american paleontologist william patten in 1912 . it is kept at the american museum of natural history in new york city .
osteichthyes huxley , 1880 ; sarcopterygii romer , 1955 ; porolepiformes jarvik , 1942 ; holoptychius agassiz , 1839 figs . 2a - c , 3a - c .
new material from the upper devonian ( frasnian ) fram formation of ellesmere island , nunavut , canada , represents the second holoptychiid ( porolepiformes ) species to be described from the formation . the quality of preservation and preparation of the material enables description of underrepresented anatomy for holoptychius including the braincase ( ethmosphenoid and otico - occipital ) . the new species of holoptychius is diagnosed by , a quadrate articulation positioned on the lingual surface of the lower jaw , the presence of a marginal tooth field on all three coronoids , and the presence of a third mandibular sensory canal located dorsal to the infradentary foramina . traditional use of the name holoptychius has resulted in an overabundance of species . in recent years , efforts have been made to re - diagnose holoptychius according to discrete cranial features rather than more widely distributed aspects of scale morphology . the new species is diagnosed as holoptychius without any scales attributed to it with this new description , the recent nunavut paleontological expeditions continue to expand the fram formation ' s diverse vertebrate fauna , one that additionally includes the elpistostegalian tiktaalik roseae .
along with eusthenodon gavini , the sarcopterygians yarimba thomsoni , grenfellia meemanae and holoptychius sp . are also present . holoptychius is known only from its very distinct scales ; a second scale morphology is also present which may be similar to scales recently identified from estonia . grenfellia meemanae is known only from a partial shoulder girdle . the ornament covering the external bony surface of this girdle is very unusual and more reminiscent of a placoderm ornament .
1896 . charles lyell and john wesley judd . the student ' s lyell : a manual of elementary geology . , page 389 . . . fish have been found abundantly , and have been referred to holoptychius nobilissimus . . .
holoptychius seems to have been a particularly widespread genus of lobe - finned fish .  like relative genera ,  the body was streamlined with most of the fins in a more rearward placement on the body .  the scales were fairly large and round ,  and the tail was asymmetrical with an upper lobe far more greatly developed than the lower .  because fish are driven by a rearward propulsion of the tail they have a tendency to nosedive into the depths ,  but the effect is magnified far greater if the upper lobe of the tail is more strongly developed .  to counter this effect ,  the pectoral fins ( the forward pair near the head ) are angled to act as hydroplanes to counter this down pitching .  the pectoral fins of holoptychius are particularly large suggesting that holoptychius were particularly fast swimmers .
the distinctive scale of this large lobe - fin fish has recently been found at red hill . evidently rare at the site , holoptychius fossils are common in late devonian rock elsewhere in pennsylvania , and , along with the antiarch placoderm bothriolepis , are characteristic of fossiliferous localities belonging to the sherman ' s creek member of the catskill formation .
holoptychius is a widely distributed member of the porolepiformes , a group of medium to large lobe - fins primitively related to lungfishes ; porolepis , glyptolepis and laccognathus are also members of this group . porolepiforms were present in some marine deposits , but were most common in estuarine and freshwater habitats . their sluggish appearance has led some scientists to conclude they were ambush predators .
biogeographic relationships of the grenfell fauna and eastern australia during the late devonian were largely based on the distribution of the sinolepidae . taxa such as the sarcopterygians eusthenodon and holoptychius are well known from european and north american localities , but so far , not described from china . this may be due to the small number of sarcopterygians described , and future work may show that these taxa are also known from china .
in 1858 a remarkably fine holoptychius andersoni was met with in the fish - bed ; and this , with many other specimens , fully bears out agassiz’s conjectures for completing the form and details of the fish where his materials had been insufficient . dr . anderson thinks that the supine position of the holoptychii is of rare occurrence ; he has observed them usually to lie on their side . h . andersoni and h . flemingii are regarded by the author as specifically one , as he has not been able , in the numerous holoptychii that he has seen , to regard as distinct the differences pointed out in the descriptions of these two reputed species .
scientists who famously discovered the lobe - finned fish fossil tiktaalik roseae , a species with some of the clearest evidence of the evolutionary transition from fish to limbed animals , have described another new species of predatory fossil lobe - finned fish from the same time and place . by describing more devonian species , they ' re gaining a greater understanding of the
fish - eat - fish world
that drove the evolution of limbed vertebrates . dr . ted daeschler of drexel university and the academy of natural sciences of drexel university describes this new species he co - discovered in the canadian arctic . read more about this new species , holoptychius bergmanni , at urltoken
books : fenton , c . l . and m . a . fenton . 1958 . the fossil book : a record of prehistoric life . garden city , new york : doubleday & company , inc . janvier , p . 1996 . early vertebrates . oxford : claredon press long , j . a . 1995 . the rise of fishes : 500 million years of evolution . baltimore & london : john hopkins univ . press . scientific papers : maisey , j . g . 1996 . discovering fossil fishes . new york : henry holt & co . image credits : the reconstruction of holoptychius is copyrighted © . ( see terms of use . ) it was based on fenton and fenton ( 1958 ) .
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further reading -  a synopsis of the classification of the british palaeozoic rocks ,  with a systematic description of the british palaeozoic fossils . fasciculus 3 ,  mollusca and palaeozoic fishes  -  f .  m ' coy  -  1855 .
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other lobefins , including an unidentified lungfish , a juvenile rhizodont ( c . f . , sauripterus ) , red hill rhizodont , red hill megalichthyidid , and hyneria lindae were also found at red hill . you can also learn more about lobe - fin fishes .
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, is one of the rare porolepiform species whose the entire body is known ; more than half the other species , about thirty in all , have only been identified by their scales .
is known at various stages of growth , just like the other porolepiforms at miguasha , with specimens ranging from 8 . 5 to 47 cm long .
the fossils are often preserved in three dimensions , and the most beautiful example , discovered by william patten a century ago , is kept at the american museum of natural history in new york city .
is recognized by its strongly epicercal tail and rounded fins ( except for the pectoral fin which has a stretched leaf - like shape ) that are equipped with a very fleshy scale - covered lobe at their base .
, pays homage to the swedish professor erik jarvik ( 1907 - 1998 ) , who dedicated a large part of his life to studying sarcopterygian fossils from the escuminac formation .
attained considerable size by the end of the upper devonian based on 6 - to 10 - cm wide scales left behind by some species .
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neil shubin ( u . chicago ) : finding tiktaalik , the fossil link between fish and land animals
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from southern new brunswick , canada , adds a new locality to eastern north america and suggests the assignment of a late devonian age for the kennebecasis formation . the formation has been considered early carboniferous based on a plant assemblage including
. plant fossils likely originate from rocks overlying the kennebecasis formation , and are part of an unmapped westward extension of the carboniferous albert formation to the saint john area . the palaeobiogeographic implications of
suggest the cryptic presence of a classic late devonian fish assemblage in southern new brunswick and the possibility that tetrapod or near - tetrapod remains may be recovered from fossil - bearing horizons within the kennebecasis formation .
dans le sud du nouveau - brunswick , canada , ajoute un nouvel emplacement dans l’est de l’amérique du nord et permet d’attribuer l’âge du dévonien tardif à la formation de kennebecasis . la formation était considérée comme une unité du carbonifère précoce d’après un assemblage végétal comprenant le
. les fossiles végétaux proviennent probablement de roches recouvrant la formation de kennebecasis et font partie d’un prolongement non cartographié de la formation carbonifère d’albert en direction ouest jusqu’à la région de saint - jean . les répercussions paléobiogéographiques de la manifestation de l’
laissent supposer la présence cryptique d’un assemblage de poissons classique du dévonien tardif dans le sud du nouveau - brunswick et la possibilité d’une récupération de restes de tétrapodes ou de quasi - tétrapodes des horizons fossilifères à l’intérieur de la formation de kennebecasis .
bailey and matthew 1872 ) is late devonian in age . we provide a description of this new specimen identified as
. 1985 ; barr and white 2004 ) . formation information can be found on - line in the lexicon database , bedrock nomenclature of new brunswick . we consider the plant fossils used to date the kennebecasis formation as carboniferous ( bell 1927 ; 1960 ) are not from this formation . the rocks yielding plant fossils originate from an overlying formation that may be an unmapped westward extension of the carboniferous albert formation to the saint john area . the occurrence of
represents the only fossil known from the kennebecasis formation redbeds . given an otherwise absence of fossils from the kennebecasis formation , age determinations are extremely difficult . consequently , this discovery carries significant interest for stratigraphers and vertebrate palaeontologists .
in southern new brunswick suggests the cryptic presence of a classic late devonian fish assemblage , in particular suggesting the possibility of finding arthrodire and antiarch placoderms and tristichopterid sarcopterygians ( schultze and cloutier 1996 ) , though none have been found to date . the vast majority of devonian tetrapod localities are known to also yield remains of
the kennebecasis formation is a poorly dated clastic sedimentary sequence from southern new brunswick that unconformably overlies neoproterozoic and early paleozoic rocks ( fig . 1 ) . the kennebecasis fault separates the kennebecasis formation from early silurian rocks of the kingston group to the northwest and a fault separates neoproterozoic and cambrian rocks to the southeast ( barr and white 1998 , 2004 ) . the kennebecasis formation refers to a sequence of conglomerates and coarse - grained sandstones on the shores of the confluence of the saint john and kennebecasis rivers in southern new brunswick , canada ( williams
in the kennebecasis formation , kennebecasis island , new brunswick ( 1 ) . plant localities reexamined for this study ( 2 , 3 ) and geological survey of canada sites reported for plants ( 4 ) and
( 5 ) are likely early carboniferous age . kennebecasis formation indicated as currently mapped .
the relationship of the kennebecasis formation to the memramcook formation to the east is uncertain . the memramcook formation is dated as fammenian to tournaisian and may be in part laterally equivalent to the late devonian to early carboniferous albert formation . recent maps show the kennebecasis formation as younger than the memramcook formation ( barr and white 2004 ) ; however , it may be equivalent to the lowest part of the memramcook formation .
the specimen described here was found on kennebecasis island in the red sandstones of the kennebecasis formation ( fig . 1 , locality 1 ) . the age of the kennebecasis formation ( williams
. 1985 ) as described by hayes ( 1927 ) and hayes and howell ( 1937 ) , has been based on plants found in grey to brown siltstone and sandstone ( fig . 1 , localities 2–4 ) . the early carboniferous age was determined by bell ( 1927 , 1960 ) who used the plants to compare it to the horton group in nova scotia . the most recent geology maps place the kennebecasis formation as middle lower carboniferous ( mcleod
. 1994 ; currie 1997 ; barr and white 2004 ) or as part of a late devonian - carboniferous package ( barr and white 1998 ; mcleod and johnson 1999 ) , and it is clear that the age is still uncertain . the discovery of a fossil vertebrate , here identified as
sp . , suggests a late devonian age , approximately equivalent to the escuminac formation of gaspé ( miguasha ) and the perry formation of southwestern new brunswick . this age determination disagrees with the early carboniferous age based on plants ( bell 1960 ) .
we argue below that the plant fossils are not from the kennebecasis formation as originally described by bailey and matthew ( 1872 ) . a review of plant and arthropod fossils , our preliminary field studies , and early descriptions of the history of the mapping of the formation suggest that the kennebecasis formation , as defined ( bailey and matthew 1872 ; hayes 1927 ; alcock 1938 ; williams
. 1985 ) , does not include the plant and arthropod - bearing strata previously described from kennebecasis island ( copeland 1957 ; bell 1960 ) and the milkish head area ( matthew 19 ) . the fossiliferous outcrops on the north shore of kennebecasis island ( fig . 1 , locality 2 ) ( wilson 1914a , b ; bell 1960 ) and at polly sams point ( fig . 1 , locality 3 ) on milkish head ( nbm collection ) that contain a
flora ( matthew 19 ; wilson 1914a ; bell 1960 ) and conchostracan remains ( copeland 1957 ) may be part of the albert formation , not currently recognized in the saint john area . further mapping will be required to determine the position of the plant - bearing beds . however , we tentatively retain them as early carboniferous and predict that the plant - bearing beds are at least equivalent in age to the albert formation and overlie red conglomerates and sandstones of the kennebecasis formation . early suggestions by ells ( 1906 ) that the kennebecasis rocks ( the red conglomerate - sandstone typical of the kennebecasis formation ) are overlain by grey plant - bearing beds of lower carboniferous age , would seem to agree with this and will require observations from a direct geologic contact .
almost all of the early work aimed at determining the age of the kennebecasis formation was published in annual reports of the geological survey of canada with little detail concerning fossil locations . the most recent survey map ( currie 1997 ) does not include the most notable fossil locations represented by gsc site numbers . preliminary field assessment to discover plant localities described from the early 1900’s suggest these localities are silty grey beds exposed on the north shore of the island ( fig . 1 , locality 2 ) and brown sandstone beds at polly sams point and sea dog cove on milkish head ( fig . 1 , locality 3 ) . plant - bearing beds on the north shore of kennebecasis island contain abundant plant fragments in a fine - grained rippled unit , typical of the albert formation further west near norton ( falcon - lang 2004 ) . similarly ,
recovered at polly sams point and the flora identified by g . f . matthew from ‘milkish’ ( new brunswick museum collection ) are also typical of the albert formation . ‘milkish’ samples likely originated from outcrops on the mainland at milkish head or west of kennebecasis island ( fig . 1 , locality 4 ) . the new brunswick museum collections also include a single , partial fish fossil from
milkish , n . b .
. the specimen ( nbmg 3085 ) , from a brown sandy sediment , belongs to an actinopterygian cf .
, also typical of the albert formation fauna at norton ( miller and mcgovern 1997 ) and albert mines ( lambe 1910a ) . however , the material consists of only a patch of articulated scales and a partial median fin , and so is not very diagnostic . nevertheless , all these specimens come from a greenish grey siltstone that is consistent with the lithology of albert formation beds , and are therefore of dubious provenance in the kennebecasis formation .
comprise red sandstone interbedded with coarse , angular conglomerate typical of the kennebecasis formation . so far plants have not been recovered in these sandstone beds , with
examination of the red sandstones of the kennebecasis formation over the past 20 years by one of us ( rfm ) has failed to produce any fossil material . generally considered unfossiliferous , the sandstone and conglomerate units of the kennebecasis formation have been largely unexplored for fossils . field work in 2005 ( rfm ) resulted in a single locality producing vertebrate remains in a red sandstone interbedded with conglomerate . the specimen is reposited in the new brunswick museum palaeontology collection ( nbmg ) .
material : nbmg 13038 ( new brunswick museum ) , a dis - articulated skeleton ( fig . 2a ) preserved mostly as a natural mould , consisting of isolated left and right dentaries , patches of scales ( fig . 2b , c ) , an isolated maxilla , left and right cleithra , left entopterygoid , gular plates and several dermal skull bones , most likely representing a single individual . the individual elements are well - preserved showing pit - lines , sensory canal pores , complete teeth and an unbroken denticle field on the entopterygoid . the dermal bones are ornamented by coarse , evenly distributed , raised tubercles of variable size .
locality : minor fine - grained sandstone unit of the kennebecasis formation , approximately 1 meter above the contact with a coarse conglomeratic facies , southeastern shore of kennebecasis island , new brunswick , canada ( 45°19 . 108n ; 66°08 . 624w ) .
sp . from the kennebecasis formation of southern new brunswick . approximately 75 to 100 scales preserved on the block . scale = 10 cm . b ) close up of dentary . scale = 1 cm . c ) close up of scales adjacent to dentary . scale = 1 cm . abbreviations : de . , dentary ; gu . , gular plate ; sc , area of scales indicated by arrows .
the specimen ( fig . 3a - c ) can be confidently assigned to the genus
on the basis of its unique and highly characteristic scale morphology ( ørvig 1957 ) in combination with a number of other distinctive skull and postcranial characters that indicate both sarcopterygian and porolepiform identity . the scales of nbmg 13038 are comparable to those of
sp . from the kennebecasis formation of southern new brunswick . largest part showing disarticulated partial skeleton ( a ) ; partial counterpart ( b ) ; close - up of two scales seen in a ( c ) . scale = 3 cm . abbreviations : clth . , cleithrum ; de . , dentary ; entp . , entopterygoid ; gu . , gular plate ; id . 4 , fourth infradentary ( surrangular ) ; ? sq . , possible squamosal ; tu . cr , tubercle crescent .
sp . from east greenland ( jarvik 1972 ) . by contrast with the tightly spaced vermicular ornament of
from that assemblage , the ornament on the cleithrum of nbmg 13038 consists of more shallow , irregular pits . the element is unornamented in the region corresponding to the postbranchial lamina . the ventral lamina is anteroposteriorly short , tapering ventrally along its anterior margin where it bears a narrow overlap for the clavicle . interestingly , this margin is somewhat concave , in contrast with that observed in
from miguasha ( cloutier and schultze 1996 ) . rather , it is somewhat similar to specimens from east greenland described by jarvik ( 1950 ) .
, and bears a similar anterior dentary lamina that likely supported a tooth whorl ( jarvik 1972 ) . this character is now considered to be a generalized feature of basal sarcopterygians as evidenced by the presence of a similar dentary lamina and accompanying internasal cavity in a number of putative stem - sarcopterygians ( zhu
. 1999 , 2001 ; zhu and yu 2002 ) and onychodonts ( see long 2001 ) . this is a feature expected to be observed in
a single fourth infradentary is present and can be identified on the basis of a v - shaped pit line and notch in its anteroventral margin , corresponding to the margin of the infradentary foramen . such foramina are known in the holoptychiid porolepiforms
specimens ( ahlberg 1991 ) and some stem - group sarcopterygians ( zhu and schultze 1997 ; yu 1998 ; zhu and yu 2004 ) . however , the overall morphology of the bone is identical to that known for
the gular plate ( fig . 3 , gu . ) is a triangular bone , broadest posteriorly and tapering anteriorly . its proportions are broader than those described for
by jarvik ( 1972 ) , but difficult to evaluate by comparison to the material from miguasha . the median overlap surface of the gular is much broader than in other
specimens and forms a distinctly concave margin into the ornamented portion of the bone . the dermal ornament is not evenly distributed over the surface , but rather is coarsest posteromedially . anteriorly , the tubercles are finer and more widely spaced . laterally , they are more densely spaced , and gradually get finer towards the posterior - most angle of the bone .
the entopterygoid is very well though incompletely preserved . it is essentially indistinguishable from that of other
after making comparisons to recent work on the perry formation by david white , ells ( 1906 , p . 131 ) stated
one of the most important of the changes made in the geological work about st . john is the transference of the dark red conglomerates and sandstones of kennebecasis bay , several miles north of the city , from the lower carboniferous to the devonian
from their previous position published in 1879 ( bailey
. 1880 ) . ells ( 1908 ) noted the devonian age of the kennebecasis rocks again in his report for 19 as he laid out the results of continued mapping in southern new brunswick .
interest in the kennebecasis fossils continued for a few years as summary reports for the years 1906 , 1908 ( wilson 1909 ) and 1909 ( lambe 1910b ; wilson 1910 ) list several collections made by geological survey of canada personnel . henri ami added 50 fossils from kennebecasis island to the survey collections in 19 ( whiteaves 1908 ) ; robert ells , lawrence lambe and william wilson added kennebecasis island and milkish creek area fossils ( part of a lot of 2 , 000 specimens ) in 1909 . wilson ( 1914a ) described the plant assemblage found earlier on kennebecasis island and identified by matthew to include
. although matthew described the plant assemblage as devonian , white ( p . 408 , in wilson 1914a ) who received a small collection to examine , believed that
the plant fragments you sent represent , almost without a doubt , a basal lower carboniferous flora . . . . . . dr . matthew , on the other hand , refers these rocks to the upper devonian
. white thought only one species of
could be identified . wilson ( 1909 , p . 184 ) described his collecting for 1908 at kennebecasis island in
rocks forming the western part of this island are grey sandstones , grits and shales : dipping n . 20° , w . at an angle of 58° . the shale is mostly fine - grained , greenish grey , breaking in places into irregular concoidal pieces . these shaly beds contain many fern stems , cordaites , lepidodendra , fronds of ferns and separate pinules in good state of preservation .
. wilson then spent two weeks at moosehorn creek collecting in the albert formation . he compared the kennebecasis island specimens to those found further east at moosehorn creek , a site within the albert formation ( falcon - lang 2004 ) .
our examination of the plant fossil locality on the north side of kennebecasis island agrees with the determination by white ( in wilson 1914a ) and bell ( 1960 ) , that specimens represent an early carboniferous assemblage and that the rocks containing plants might be part of the albert formation which crops out less than 40 km east of saint john along the kennebecasis river valley near bloomfield ( mcleod and johnson 1999 ) . bell ( 1960 ) listed six plants from kennebecasis island in his review of the horton group flora ;
made by kindle at milkish head ( fig . 1 ) and that its range is confined to the lower carboniferous . wilson ( 1915 ) in his palaeobotany report for 1914 recorded about 100 fossil plants collected by a . o . hayes from kennebecasis island , mostly
. the summary report for 1915 ( kindle 1916 , p . 200 ) listed as an addition to the survey invertebrate collections
a crustacean fragment from the carboniferous formation at kennebecasis island , n . b .
collected by bell .
and other plant remains from the northwestern shore of kennebecasis island which bell ( 1927 ) used to suggest an early carboniferous age for the kennebecasis formation . in the same report hayes and howell ( 1937 ) noted hayes had discovered abundant examples of the conchostracan
in a grey shale on the south shore of milkish head and on the most southerly point west of sea dog cove ( fig . 1 ) .
from gsc localities 1684 , 3520 and 1684 respectively . gsc 1684 is described as the lancaster formation near milkish head , east of saint john and collected by a . o . hayes , 1913 . gsc 3520 is reported to be a cove to the south of milkish head , kennebecasis bay near saint john , collected by i . r . jones , 1914 . copeland ( 1957 ) reported both of these as upper carboniferous , cumberland group , although both localities are in the kennebecasis formation as presently mapped . there may have been some error in the field notes for these sites as no cumberland group rocks have ever been identified from the milkish head area . copeland ( 1957 ) did not list
is known from miguasha ( martens 1996 ) , occurring on clay bedding planes . specimens labelled ‘
’ ( nbmg 10115 - 10117 ) from milkish are found on thin clay slabs although the source beds of these fossils has not been located . the specimens have not been identified ; however , they are not
this summary of the history of plant identification and dating of the kennebecasis formation leads us to believe the plant assemblages initially collected by ells in 1906 and described by matthew ( 19 ) , along with subsequent collections of plants and conchostracans , originate from lower carboniferous rocks overlying the devonian red sandstone and conglomerate of the kennebecasis formation ( hayes 1927 ) .
has a global distribution , known from the eastern united states ( catskill formation , uppermost famennian ; thomson 1976 ; schultze and cloutier 1996 ) , quebec ( escuminac formation , lower frasnian ; cloutier and schultze 1996 ; jarvik 1972 ) , the canadian arctic ( see kiaer 1915 in ørvig 1957 ) , greenland ( jarvik 1972 ) , numerous localities in europe , particularly the baltic states , russia , and britain , and australia ( young 1993 ; schultze and cloutier 1996 ) . since schultze and cloutier ( 1996 ) this genus has been described from the frasnian of colombia ( janvier and villarroel 2000 ) . the occurrence of definitive remains of
in the kennebecasis formation lends strong support for the assignment of a late devonian age for this formation .
. this conclusion is dubious . the reason an early carboniferous age assigned to the kennebecasis formation may be incorrect was discussed above . although bell ( 1960 ) described the lycopsids from kennebecasis island as an early carboniferous assemblage , it is possible they represent a late devonian flora such as that from red hill ( cressler and pfefferkorn 2005 ) where
tends to be a rather abundant and common component of fish faunas , frequently represented by numerous scales . such scales or any other evidence of
is lacking from any of the fossil fish beds in the albert formation , which would be in close stratigraphic apposition with the kennebecasis formation .
work by greiner ( 1977 , 1978 ) seemed to suggest that basal beds of the albert formation may have in fact been latest devonian . this conclusion was initially based on an osteolepi - form that was referred to the genus
( greiner 1977 ) known from the late devonian of the baltic and germany . however , greiner cites no characters supporting this conclusion and a recent reappraisal of this and newly collected articulated material suggests a megalichthyid affinity , quite typical of many carboniferous vertebrate faunas . recent work by the authors , involving intensive collecting in the albert formation , shows that this formation is more typical of carboniferous vertebrate assemblages , with
or any porolepiforms entirely lacking . spore analyses by st . peter ( 2003 ) indicate a tournaisian ( carboniferous ) age for the albert formation beds containing the osteolepiform remains . therefore , we do not see greiner’s conclusions as related to the problem we have addressed here .
spp . is a subject requiring considerable revision as few apomorphies can be used to diagnose the many species ( cloutier and schultze 1996 ) . consequently , we do not attempt to assign this material to any existing species nor do we attempt to establish it as a new taxon within the genus . the material is too incomplete to warrant a comparison with other known species of
sp . in red sandstone beds typical of the formation . plant - bearing beds are lithologically distinct from the red sandstone and conglomerate of the kennebecasis formation as originally defined . plant fossils , including
and other lower carboniferous horton group flora , were likely collected above an unmapped contact from rocks equivalent to the albert formation . these facts help resolve the confusion surrounding the middle palaeozoic stratigraphy in this region . it further implies that the kennebecasis formation may be in part equivalent to the well - established upper devonian memramcook formation ; however , we retain the distinction until proper stratigraphic work is accomplished . the presence of
opens the possibility for the kennebecasis formation to yield additional late devonian fishes and possibly even tetrapods .
agassiz , j . l . r . 1839 . fishes of the upper ludlow rock . in the silurian system , part 1 . founded on geological researches in the counties of solop , hereford , radnor , montgomery , caermarthen , brecon , pembroke , monmouth , gloucester , worcester , and stafford : with descriptions of the coal - fields and overlying formations . edited by r . i . murchison . london , john murray , pp . 605–6 .
ahlberg , p . e . 1991 . a re - examination of sarcopterygian interrelationships , with special reference to the porolepiformes . zoological journal of the linnean society , 103 , pp . 241–287 .
alcock , f . j . 1938 . geology of the saint john region , new brunswick . geological survey of canada , memoir 216 . 146 p .
bailey , l . w . , and matthew , g . f . 1872 . preliminary report on the geology of southern new brunswick . geological survey of canada , report of progress , 1870 - 71 , pp . 13–240 .
bailey , l . w . , matthew , g . f . , and ells , r . w . 1880 . report on the geology of southern new brunswick , embracing the counties of charlotte , sunbury , queens , kings , st . john , and albert . geological survey of canada report of progress , 1878 - 79 , pt . d , pp . 1–26 .
barr , s . m . , and white , c . e . 1998 . geology of the kingston peninsula ( parts of nts 21g / 08 , g / 09 , h / 05 , and h12 ) , kings and queens counties , new brunswick . new brunswick department of natural resources and energy , minerals and energy division , plate 98 - 16 , scale 1 : 50 000 .
barr , s . m . , and white , c . e . 2004 . bedrock geology of the caledonian highlands of southern new brunswick . new brunswick department of natural resources , minerals , policy and planning division , plate 2004 - 138 , scale 1 : 100 000 .
bell , w . a . 1927 . outline of carboniferous stratigraphy and geologic history of the maritime provinces of canada . transactions of the royal society of canada , 21 , pp . 75–108 .
bell , w . a . 1960 . mississippian horton group of type windsor - horton district , nova scotia . geological survey of canada , memoir 314 . 112 p .
clack , j . 2005 . the emergence of early tetrapods . palaeo - geography , palaeoclimatology , palaeoecology , 232 , pp . 167–189 .
cloutier , r . , and schultze , h . - p . 1996 . porolepiform fishes ( sarcopterygii ) . in devonian fishes and plants of miguasha , quebec , canada . edited by h . - p . schultze and r . cloutier . verlag dr . friedrich pfeil , munich , pp . 248–270 .
copeland , m . j . 1957 . the arthropod fauna of the upper carboniferous rocks of the maritime provinces . geological survey of canada , memoir 286 . 110 p .
cressler , iii , w . l , and pfefferkorn , h . w . 2005 . a late devonian isoetalean lycopsid , otzinachsonia beerboweri , gen . et sp . nov . , from north - central pennsylvania , usa . american journal of botany , 92 , pp . 1131–1140 .
currie , k . l . 1997 . geology , saint john - st . george region , new brunswick ( parts of 21g and 21h ) . geological survey of canada , open file 3418 , scale 1 : 100 000 .
ells , r . w . 1906 . southern new brunswick . geological survey of canada , summary report for 1906 , pp . 131–139 .
ells , r . w . 1908 . surveys in southern new brunswick . geological survey of canada , summary report for 19 , pp . 74–76 .
falcon - lang , h . j . 2004 . early mississippian lycopsid forests in a delta - plain setting at norton , near sussex , new brunswick . journal of the geological society , london , 161 , pp . 969–981 .
falcon - lang , h . j . , and miller , r . f . 20 . marie stopes and the fern ledges of saint john , new brunswick . in the role of women in the history of geology . edited by c . burek and b . higgs . geological society of london , special publications , 281 , pp . 277–245 .
gesner , a . 1839 . first report on the geological survey of the province of new brunswick . henry chubb , st . john . 87 p .
greiner , h . 1977 . crossopterygian fauna from the albert formation , new brunswick , canada , and its stratigraphicpaleoecologic significance . journal of paleontology , 51 , pp . 44–56 .
greiner , h . 1978 . late devonian facies inter - relationships in bordering areas of the north atlantic and the palaeogeo - graphic implications . palaeogeography , palaeoclimatology , palaeoecology , 25 , pp . 241–263 .
gross , w . 1941 . über den unterkiefer einiger devonischer crossopterygier . abhandlungen der preußichen akademie der wissenschaften , mathematisch - naturwissenschaftliche klasse , 7 , pp . 1–51 .
hayes , a . o . 1914 . geology of the st . john map - area , new brunswick . geological survey of canada , summary report for 1913 , pp . 228–243 .
hayes , a . o . 1927 . bituminous shales and other mineral occurrences in the vicinty of sussex , new brunswick . geological survey of canada , summary report for 1925 , part c , pp . 125–131 .
hayes , a . o . , and howell , b . f . 1937 . geology of saint john , new brunswick . geological society of america , special papers number 5 . 146 p .
huxley , t . h . 1880 . on the application of the laws of evolution to the arrangement of the vertebrata , and more particularly of the mammalia . proceedings of the zoological society of london , 43 , pp . 649–661 .
janvier , p . , and villarroel , c . 2000 . devonian vertebrates from colombia . palaeontology , 43 , pp . 729–763 .
jarvik , e . 1942 . on the structure of the snout of crossopterygians and the lower gnathostomes in general . zoologiska bidrag , uppsala , 21 , pp . 235–675 .
jarvik , e . 1950 . middle devonian vertebrates from canning land and wegeners halvö ( east greenland ) , part ii : crossopterygii . meddelelser om grønland , 96 , pp . 1–132 .
jarvik , e . 1972 . middle and upper devonian porolepiformes from east greenland with special reference to glyptolepis groenlandica n . sp . meddelelser om grønland , 187 , pp . 1–3 .
johanson , z . , and ritchie , a . 2000 . rhipidistians ( sarcopterygii ) from the hunter siltstone ( late famennian ) near grenfell , nsw , australia . mitteilungen aus dem museum für naturkunde in berlin , geowissenschaftliche reihe , 3 , pp . 111–136 .
kindle , e . m . 1916 . report of the stratigraphical palaeontologist . geological survey of canada , summary report for 1915 , pp . 198–205 .
lambe , l . m . 1910a . contributions to canadian palaeontology , volume iii , part v . palaeoniscoid fishes from the albert shales of new brunswick . canada department of mines , memoir no . 3 . 69 p .
lambe , l . m . 1910b . palaeontology and zoology . geological survey of canada , summary report for 1909 , pp . 269– 273 .
long , j . a . 2001 . on the relationships of psarolepis and the onychodontiform fishes . journal of vertebrate paleontology , 21 , pp . 815–820 .
martens , t . h . 1996 . conchostraca ( phyllopoda , crustacea ) from the escuminac formation . in devonian fishes and plants of miguasha , quebec , canada . edited by h . - p . schultze and r . cloutier . verlag dr . friedrich pfeil , munich , pp . 112–113 .
matthew , g . f . 19 . on some new species of silurian and devonian plants . transactions of the royal society of canada , 3rd series , 1 , pp . 185–197 .
mcleod , m . j . , and johnson , s . c . 1999 . bedrock geological compilation of the sussex map area ( nts 21 h / 12 ) , kings and queens counties , new brunswick . new brunswick department of natural resources and energy , minerals and energy division , plate 99 - 21 , scale 1 : 50 000 .
mcleod , m . j . , johnson , s . c . , and ruitenberg , a . a . 1994 . geological map of southwestern new brunswick . new brunswick department of natural resources and energy , mineral resources , map nr - 5 , scale 1 : 250 000 .
miller , r . f . , and mcgovern , j . h . 1997 . preliminary report of fossil fish ( actinopterygii : palaeonisciformes ) from the lower carboniferous albert formation at norton , new brunswick ( nts 21 h / 12 ) . in current research 1996 . edited by b . m . w . carroll . new brunswick department of natural resources and energy , minerals and energy division , mineral resource report 97 - 4 , pp . 191–200 .
ørvig , t . 1957 . remarks on the vertebrate fauna of the lower upper devonian of escuminac bay , p . q . , canada , with special reference to the porolepiform crossopterygians . arkiv för zoologi , 10 , pp . 367–426 .
romer , a . s . 1955 . herpetichthyes , amphibiodei , choanichthyes or sarcopterygii ? nature , 176 , pp . 126 .
schultze , h . - p . , and cloutier , r . 1996 . comparison of the escuminac formation ichthyofauna with other late givetian / early frasnian ichthyofaunas . in devonian fishes and plants of miguasha , quebec , canada . edited by h . - p . schultze and r . cloutier . verlag dr . friedrich pfeil , munich , pp . 348–368 .
st . peter , c . 2003 . revisions to lower carboniferous horton group stratigraphy in new brunswick , canada . in abstracts with programs , geological society of america , northeastern section 38th annual meeting , 35 , p . 19 .
thomson , k . s . 1976 . the faunal relationships of rhipidistian fishes ( crossopterygii ) from the catskill ( upper devonian ) of pennsylvania . journal of paleontology , 50 , pp . 1203–1208 .
whiteaves , j . f . 1908 . surveys in southern new brunswick . geological survey of canada , summary report for 19 , pp . 105–109 .
williams , g . l . , fyffe , l . r . , wardle , r . j . , colman - sadd , s . p . , and boehner , r . c . 1985 . lexicon of canadian stratigraphy , volume vi , atlantic region . canadian society of petroleum geologists , calgary . 572 p .
wilson , w . j . 1909 . summary report dealing with the field work in connexion with the collection of palaeontological material from the devonian and lower carboniferous of new brunswick . geological survey of canada , summary report for 1908 , pp . 183–185 .
wilson , w . j . 1910 . palaeontological material from the devonian and carboniferous of southern new brunswick . geological survey of canada , summary report for 1909 , pp . 274–276 .
wilson , w . j . 1914a . summary report dealing with the field work in connexion with the collection of palaeontological material from the devonian and lower carboniferous of new brunswick . geological survey of canada , summary report for 1912 , pp . 4–410 .
wilson , w . j . 1914b . palaeobotany . geological survey of canada , summary report for 1913 , pp . 322–326 .
wilson , w . j . 1915 . palaeobotany . geological survey of canada , summary report for 1914 , pp . 130–134 .
young , g . 1993 . middle paleozoic macrovertebrate biostratigraphy of eastern gondwana . in palaeozoic vertebrate biostratigraphy and biogeography . edited by j . a . long . johns hopkins university press , pp . 208–251 .
yu , x . 1998 . a new porolepiform - like fish , psarolepis romeri , gen . et . sp . nov . ( sarcopterygii , osteichthyes ) from the lower devonian of yunnan , china . journal of vertebrate paleontology 18 , pp . 261–274 .
zhu , m . , and schultze , h . - p . 1997 . the oldest sarcopterygian fish . lethaia 30 , pp . 293–304 .
zhu , m . , and yu , x . 2002 . a primitive fish close to the common ancestor of tetrapods and lungfish . nature 418 , pp . 767–770 .
zhu , m . , and yu , x . 2004 . lower jaw character transitions among major sarcopterygian groups - a survey based on new materials from yunnan , china . in recent advances in the origin and early radiation of vertebrates . edited by g . arratia , m . v . h . wilson , and r . cloutier . verlag dr . friedrich pfeil , munich , pp . 271–286 .
zhu , m . , yu , x . , and janvier , p . 1999 . a primitive fossil fish sheds light on the origin of bony fishes . nature 397 , pp . 6–610 .
zhu , m . , yu , x . , and ahlberg , p . 2001 . a primitive sarcopterygian fish with an eyestalk . nature 410 , pp . 81–84 .
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( ) british antarctic ( terra nova ) expedition 1910 - . source is original
beacon sandstone , granite harbour reference : - ( ) british antarctic ( terra nova ) expedition 1910 - . source is original
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his geological remarks on dura den , the author described the sedimentary strata in the vicinity as consisting of ( in ascending order ) —1 . grey sandstone , the equivalent of the carmylie and forfarshire flagstones , with
, 3 . conglomerates , marls , and cornstone , with few and obscure fossils . 4 . the yellow sandstone , rich in remains of
and other fishes , and about 300 or 400 feet in thickness . this sandstone is seen to rest unconformably on the clashbennie series of the old red at the northern opening of the den , and at the southern end is unconformably overlain by the carboniferous rocks . it is also exposed beneath the lower coal - series of cults , the lomonds , binnarty , and the cleish ilills . it is seen also in western scotland ( renfrewshire and ayrshire ) , and in berwickshire and elsewhere in the south , with its pterichthyan and holoptychian fossils . in the author ' s opinion it is entirely distinct from the “yellow sandstone” of the irish geologists .
at dura den one thin bed in the yellow sandstone especially teems with fossil fish . the pamphractus - bed , towards the top of this thick deposit , is the only other stratum bearing fossil remains .
dr . anderson also offered some remarks on the glyptopomus minor ( agass . ) , the specimen of which was obtained from this locality ; and he drew attention to two as yet undescribed fishes * also from dura den .
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