FISHES OF THE TRIASSIC SYSTEM

274 PROCEEDINGS OF THE NATIONAL MUSEUM

E. FISHES OF THE TRIASSIC SYSTEM

For the purpose of the present contribution it is not considered practicable to enterinto alengthy or detailed account of thelarge store offossilfishes from Mesozoic andCenozoic horizons belonging tothecollections oftheUnitedStatesNational

Museum,

inviewofthe fact that the majority of these belong to well-known genera, the anatomical structure of which approaches ratherclosely to that of

modern

forms, and the systematic position ofwhich is pretty cer- tainly ascertained.

A

fewgeneralremarksonthecollection of post- Palaeozoicfishesasa whole, followed

by

particularnotice ofcertain

new

orespecially interesting species, willbesufficientfor this section ofthereport.

Triassic fishes are extremely wellrepresented in the

Museum

col- lection.

From

the Triassic rocks of eastern North America very extensivecollectionswere

made

intheConnecticut Valley region dur-

1Arestoration ofthe skeletonofChdrodus granulosus(Young)isgivenin plate5,figure1,of thismemoir andoneofPlatysvmusstriatusAgassizin plate6,figure1.

278 PROCEEDINGS OF THE NATIONAL MUSEUM.

vol.52.

ing theearly nineties

by

Mr.S.

Ward

Loper,ofMiddletown, Connec-

ticut, under the direction of Prof.

W.

M. Davis; and in particular, the specimens

obtamcd by him

^{from oneortwolocalitiesnearGuil-}

ford,Comiecticut, deserve noticefortheexcellence of theirpreserva- tion, and the clearness with which certain doubtful pokits in the anatomical structure are revealed. Several typical examples from thislocahtyhave beenselected for illustration in plates 12 and13.

A number

of fineexamplesofSemionotidfishesfrom the

Newark

systemof

New

Jersey (pi. 12,fig. 3),and afew fromthe

Richmond

coalfieldofVirgmia,both^of

Upper

Triassic age, arecontamedinthe collection.

An

exceptionallyperfectspecimenof Semionotus elegans

Newberry

(Cat.No.8109)from Boonton,

New

Jersey,is

shown

inplate 15,figure3.

The

genusDichjopyge,founded

upon

anearlycomplete

fish from the

Richmond

basin, ^is mvested with

some

historical mtereston account ^of its having been studied

by

Charles Lyell, Phihp Grey Egerton, and Louis Agassiz during the fourth decade ofthelast century.^

From

the Cordilleran region ^{of this} country a large quantity of fish-remains,

now

in the National

Museum

collection,

was

obtained

by

Dr.

CD.

Walcottinthe years1879-80,

when

exploring

theKanab Canon

of

Utah

and Arizona as hisfirst

work

in connectionwith the UnitedStates Geological Survey. Dm-ingthe pastdecade

some

fur- ther remains from the Shinarump group ^of southwestern Colorado have been obtained

by

Dr.

Whitman

^Cross,

^who

has

shown

that there are strong reasons for correlating theTriassic portion of this group,asdefined

by

Powell,withthe lower part^ofthe Doloresforma- tion ofColorado. Inthe courseofhis discussion of the

homo

taxial relations of this group. Doctor Cross introduces a sectionin

Kanab

Valley, Utah,

made by

Doctor Walcott in 1879,

showmg

^theprecise

position ofthebeds (Nos. 11 and 13)

whence

thefishremainswere derived.

A

reptilianfauna occurs in the Shinarump conglomerate, and thefish beds^ofthe

Kanab

sectionoccur

some

hundredsof feet abovethismember.^

Although the fish-remains from this section are extremely frag- mentary,it ispossible torecognizewithcertaintythe presenceofthe genera Lepidotus and Plwlidopliorus; and on first examining this material the writer concluded from their general aspect that they indicated a foreshadowuig of Liassic conditions.^ During the past year, however,

more

complete specimens of the genus Lepidotus have beenstudied, thelargestand best preservedofwhichareillus-

>Lyell'spaperon thecoal field oftheJamesRiver,nearRichmond,Va.,isfoundinQuart.Joum.

Geol.Soc,vol.3,1847. SomeinterestingcorrespondencebetweenLyellandEgerton has recentlycometo light,andispublishedinthe Annalsofthe CarnegieMuseum(vol.9,1914,pp.^139-148).

across,W. TheTriassicportionoftheShinarumpGroup. Joum.Geol., vol.IG,1908,pp.^97-123. A

Devonianfishfaunafromthis regionisalsomentionedbyDr. Walcott.

'Triassic Fislies ofConnecticut. Conn. State Geol. Nat.Hist.Surv.Bull.18,1911, p. 35.

N0.2lt7. FOSSIL

FISHES

IN

NATIONAL MUSFVM— EASTMAN. 279

trated inthefigures atthebottom^ofplates 12and 13. Although a precise specific determination is impossible, nevertheless a near comparison

may

be

made

with the Semionotid form described

by

MichaelasProlepidotusgallineJci,from the

Upper Keuper

ofSilesia.^

(Aseriesofnaturally associated Lepidotid scales is

shown m

^plate

10,figure7.)

The

characterof the

Kanab

Valleyfish-faunacertainl}^

differsmarkedly from that of the eastern United States, the differ- ences beingprobablyattributabletothedifferentnatureofthesedi- mentationinthetworegions.

A

very importantsuite ofmaterialfrom the TriasofSouthAfrica comprising well-preserved specimens ^of Semionotus capensis

Wood- ward

is contaiaed ui the collection.

The

anatomical structure of thisspecieshasbeencarefullyinvestigated

by

thelateDr. E.Schell- wien.2 Finally, mentionshould be

made

ofa smallbut interesting collection of fossil fishes from the

Hawkesbury

Series at Gosford,

New

SouthWales,onespecunen

among

the

number

being apeculiar formofBelonorTiyncIius,presentlytobedescribed.

The

ichthyicfauna of this formation has been investigated principally

by

Dr. A. S.

Woodward.^

Family

CATOPTERIDAE Woodward.

This family comprisesTriassicfusiformfishesresembhngPalaeoni- scids ingeneralstructure,but havinganabbreviate heterocercaltail,

and lepidotrichiawhich only shghtly exceed theradials innumber.

The

latteralsoappeartobeformedchieflyofone proximalsegment.

The

ganoidscalesarerhombic; the teeth slenderandconical.

The

family is accompanied in the Trias

by

other chondrosteans which

became

eel-shaped (Belonorhynchidae)anddiedoutduring that period. Still others, whichgradually lost theirscaly covering and head bones (CJiondrosteus)continuedtosurvive, andarerepresented

by

thesturgeons oftheexistingfamia.

The

relations of thisfamily are,therefore, with

modem

sturgeons ratherthan withthe

two

sur- vivinggeneraofProtospondyh,

Amia

andLepidosteus.

Genus

CATOPTERUS

Redfield.

The

type-species of thisgenus, C. gracilis,

was

described

by

J, H.

Redfieldin 1837.

A

decadelaterthesecond

known

species of Catop- terus

was

described

by

SirPhiUp GreyEgerton,

when

the

new

genus Dictyopyge

was

estabhshed

by him upon

the evidence of fairly well preservedspecimens from the

Richmond

coal field ofVirginia.

1Michael,R. Uebereine neue Lepidosteiden-Gattimg ausdemoberenKeuperOberschlesiens. Zeitscfar.

Deutseh.Geol. Ges., vol. 45, 1893,pp.^710-729.

2Schellwien,E. UeberSemionotus Ag. Phys-okon.Ges.,Konigsberg,1901.

3Woodward,A.S. Thefossilfishes OftheHawkesburySeries atGosford. Mem.Geol.Surv.NewSouth Wales,Palaeont.,No.4,1890.

*

280 PROCEEDINGS OF THE NATIONAL MUSEUM.

vol.52.

CATOPTERUSGRACILISRedfield.

Plate12,figs.1,2; plate13,figs.1,2.

Catoptei-us gracilisJ.H. Redfield, Ann.LyceumNat.Hist.,N.Y.,vol.4,1837, p. 37, pi.^1.

—

Newberry,Monograph. U.S.Geol. Surv.,vol. 14, 1888. p. 55, pi. 16,figs.1-3.—Eastman,Conn.State Geol. Nat. Hist. Surv. Bull.18, 1911.

Among

themostinstructive specimensthat have

come

under the

^Titer's observation for elucidating the

much

vexed subject of the cranial osteology of this species and genus, first mention should be

made

ofoneoftheoriginalcotypesofC. gracilis,

now

preservedinthe

Peabody Museum

atYaleUniversity; andscarcelyinferiorinimpor- tanceareseveralsmallspecimensfromtheConnecticut Valley region belongingtotheUnitedStatesNational

Museum. Two

oftheselat- ter,from

Durham,

Connecticut,are

shown

inthe accompanyingplate 12,andalargeronefromGuilford, in plate 13,figm-e1.

The

original of plate 13, figure 2, from the Trias of

Dm-ham,

Connecticut, is of valuefor illustrating

how

^thedepthof

body

isapparently increased

by

accidentalcrusliing prior to fossihzation. In thisspecimen it is

easy to distinguish the

row

^of dorsal ridge-scales which has been pushed over to one side and occupies a position at

some

distance belowtheuppercontourhne ofthefossil. Examples^ofmechanical deformationof thiskind pointtothe extremedegreeofcaution that

isnecessaryinattemj^tingtotracethedorsalandventralcontoursof crushed specimens of this and the accompanying genus Semionotus intheTriassicrocksofNorthAmerica.

To

speak

more

particularly of the cranial osteology, it

must

be admitted that scarcely anything can be added to the facts already known.

The

bones formingthecranial roof are asarulefu-mly coal- escedand theirsutm-esconcealed

by

thetubercular ornamentation.

Apparentlythe superior borderoftheorbitsisformed

by

thelarge- sized frontals, whicharebounded behind

by

theparietals (the latter separated in the median Hne

by

a small-sized supra-occipital) and squamosal.

The

^inferiorborderoftheorbitisformed

by

theexpanded posteriorportion ofthemaxilla, whichisofrelativelylargesizeand decidedlyPalaeoniscid-like inform. Thisplatebearsnumerousfine, acutely conical teeth, and^{there is} also present a small dentigerous premaxilla, which is often found detached from the other

mouth-

parts.

Just

how

^thefacialplatesarearrangedinthespace lyingbetween the orbit and shoidder-rcgion (clavicle) is difficult to determine.

Newberry's interpretation of the elements covering this area in a singlespecimenstudied

by him

isopento serious question.

At

least onepostorbitalispresentinitsnormalposition beliindtheeye,and there

may

possiblybe another,or suborbital,belowit. Behindthese platesisthearea

commonly

occup'iod

by

theoperculum andsuboper-

NO. 2177. FOSSIL

FISHES

IN

NATIONAL 2IUSEVM—EASTMAN. 281

culum,but the preoperculiimwas probably

much

reducedandnearly concealed byadjacent elements.

Formation and locality.

— ^Upper

^Trias; Connecticut Valley and

New

Jersey.

Family

BELONORHYNCHIDAE Woodward.

Ofthisfamilyof Triassicchondrosteans, only asinglegenuswhich

is capable ^of satisfactory deimition has hitherto been discovered.

ThisisBelonorhynchus, represented

by

aboutadozenspecies.

Under

the term of Sauriclitliys Agassiz are provisionallyincluded several species which

may

be generically identical with Belonorhynchus, as suggested

by

OttoReis/ but for the present,following

Woodward's

example, it seems preferable to retain the estabhshed systematic arrangement.

Two

representativesofBelonorhynchushave beendescribedbyA.S.

Woodward

from the

Upper

Trias of Gosford,

New

South Wales.

Thesehave been

named

B.gigasandB.gracilis,anddifferfromother

known

species intheform of dermalscutesand minordetails ofthe finsand scales.

From

the

same

horizon and locahty asingle very pecuhar specimen hasbeen obtainedwhichrecallsin

some

respects, suchas

body

contourandcharacteroftheremotedorsalfin,thesmal- lerofthesespecies (B. gracilis).

But

theconformationofthehead and obtuse, romided snout does not agree at allwith the features which

we

areaccustomedto associatewith

members

ofthisgenusfor the corresponding region; and the specimen in question is clearly anomalousin thisregard.

The

specimen just referred to belongsto the

Museum

collection, andis

shown

in plate14, figiu-e 3. Itis

embedded

inthe

same

slab of sandstonein whicharecontained severalspecimensof Cleithrolepis.

Semionotus, andDictyopyge, the wholeblock being enteredunderthe catalogue

number

1842. Unfortunately the condition of thespeci-

men

does not permitofacloser identificationthan tosuggest being includedasanaberrant representativeofthe Belonorhynchidae,with

much

abbreviated snout. Suturesin thecranial shield are notdis- tinguishable,anditwould appearasifthe actualbonesubstancehad been fractured and exposed to weathering.

Under

such circum- stances

we

are notwarrantedinestabhshing a

new

genus orspecies

upon

theevidence ofthesolitaryspecimenbeforeus,but afigure of it is giveninthehope that further enhghtenment

may

be at

some

latertime forthcoming.

1Geogn.Jahresb., 1891, p. 149,

282 PROCEEDINGS OF THE NATIONAL MV8EUM.

^vol.52.

Family

SEMIONOTIDAE Woodward.

A

study^ofthe charactersof thisfamilyshowsthat thegenerain- cluded under it are fully developed Protospondyli, that is to say, they belong clearly to that large group of "ganoid" fishes which

floui-ished chiefly during the Triassic and Jurassic periods, butde- chned rapidly, and is represented at the present

day by

only

two

fresh-water genera, Lepidosteus and Amia.

From what

ancient stock the Semionotidae and other Protospondli are descended

we

do notprecisely know, but it

may

reasonably be inferred that the latePalaeozoicforermmers{AcentropTiorus^eiQ,.) ofthehigher suborder werederived from a modified typeof chondrostcan.

Beyond

this,

when we

inquire as totheorigin of theChondrostei themselves,

we

find but fewfacts forour enlightenment. Theirorigmis at least as ancientasthatofthe "fringe-finned ganoids,"butthereisasyet

no

evidenceofa genetic connectionbetweentheChondrostei andcross- opterygians. Enough, however,has been ascertained to

show

that alreadyinthe Triastmd probably evenearlierthedivergencebetween chondrosteansand Protospondyli

was

stronglymarked.

SEMIONOTUS ELEGANS(Newberry).

Plate15,fig.3.

Ischypterus elegansNewberry,Monogr. U.S.Geol. Surv.,vol.14,1888, p. 37, pi.7, fig.2;pi. 10,fig.1; pi. 14,figs.1,2.

IschypterusviodestusNewberry,Monogr. U.S.Geol. Surv.,vol. 14, 1888, p. 38, pi.9, figs. 1, 3.

The

originalspecimens servingfortheestablishmentof thisspecies are

now

preserved in theAmerican

Museum

ofNatural History in

New

York.

They

arenearlycompletefishes,but

much

crushed,and in becomingflattened their characteristicfeatures have

become

ob- scured.

A

large-sized specimen, 17 cm. in total length, and

more

perfectlypreserved than anyother example of this speciesseen

by

thewriter, is contained

m

^theUnited States National

Museum

col- lection (Cat.No.8109). Itisfromthe TriasofBoonton,

New

Jersey, andrepresentedin

my

plate15,figure3.

Genus

LEPIDOTUS

Agassiz.

Syn.ProlepidotusMichael.

Numerous

species of thisgenushave beendescribed,but

many

are imperfectlyknown.

No

indicationsofthegenushave yet beenre- ported from this country, with the exception of certain isolated scalesfromthe

Kiowa

shales(Cretaceous) ofKansas.

The

following

new

speciesisregarded asstandingincloserelationswithL.gallineki (Michael),from theRhaeticof

Upper

Silesia.

NO. 2177. FOSSIL

FISHES

IN

NATIONAL MUSEUM— EASTMAN. 283

LEPIDOTUSWALCOTTI, newspecies.

Plate12,fig.4;plate13,fig.3.

An

imperfectlydefinablerobustspecies ofmoderatesize, attaining atotallengthofabout30 cm., andexhibitingsimilarproportionsas inL.minorandL.notopterus; apparentlycloselyrelated tothe

Upper

TriassicL. gallineld. Scalessmooth,thick, deeply overlapping, not serrated; clavicle extremely massive; head parts and paired fins

not observed; dorsal with about 15 stout rays. (Cat. No. 8119, U.S.N.M.)

It is to be regretted that no complete individuals of this early representativeofthegenushaveyetbeendiscovered.

The

examples figured in the accompanying plates are the

most

perfectwhich are containedⁱⁿ thecollection

made by

Doctor Walcott duringhisfirst

work

in connection with the United States Geological Survey. Al- thoughthecollectionswere

made more

than35 yearsago

by

Doctor Walcott,inwhose honorI have pleasure in dedicating the species, it doesnot appear that any other person has obtained fishremains from the

Utah

Trias, nor has any other species of Lepidotus been described from thiscountry.

Althoughfishremains were found

by

DoctorWalcottinconsidera- bleabmidancehithe

Kanab

section,nootherfossilvertebrateswere noticed

by

hmi. BesidesLepidotus, the only othergenusthat can becertainly identified

among

theremainsisPholidopliorus,evidently ofprimitivecharacter.

A

singlesaurian tooth,perhapscrocodilian, has also been recognized. This latter is significant in view of the factthataTriassicsaurianfaunahasbeen found on the LittleColo- radoinArizona,intheSan JuanValley,Utah, notfarfromthe Colo- rado River,atvarious pointsinsouthwestern Coloradowhere Doctor Cross hasbeen engaged in survey

work

for

many

years, and in the vicinity ofLander,

Wyoming,

where Dr. S.

W.

Williston has

made

collections. Li the opinionofDoctorCross, as stated to the writer in a personalcommmiication, "thehorizon exploited

by

Williston^

in

Wyoming

is the

same

as that which furnished the vertebrates described

by

Lucas^{^}inArizona.

The

section

made by

DoctorWalcottinthe

Kanab

Valley,Utah,

was

firstpublished

by

DoctorCross, as alreadyremarked, in 1908.

ThatpartofitlyingabovethePermian^ishere introducedinorderto

show

therelations ofthebedswhichcarryavertebrate famia.

SECTION IN KANAB VALLEY, UTAH, MADE BYC. D. WALCOTT, 1879.

Jurassic.

Feet.

1.WhiteCliffsandstone, massive, cross-bedded,light gi'ay,brokenintofive

principal beltsbyhorizontallines ofbedding ⁵⁸⁵

1williston, S.W. Noticeofsome newreptilesfrom theUpperTriasofWyoming. Journ. Geol., vol.

12,1904,pp. 68S-697.

>Lucas, F. A. Vertebratesfromthe TriasofArizona. Science, vol.14,1901, p. 376. Anewbatrachian andanewreptilefrom the TriasofArizona. Proc.U.S.Nat.Miis., vol.27,1904,pp. 193-195.

284 PROCEEDINGS OF THE NATIONAL MV8EVM.

vol.52.

SECTIONINKANAB VALLEY, UTAH, MADE BYC. D. WALCOTT, 1879

—

^Continued.

Triassic.

Feet.

2. Vermilionsandstone; cross-bedded, friable, readily disintegrating, form- ing thefoothillsandslopetothemore compactsandstonesatthe northern

endofVermilionCliffCanyon G50

3. Gray and reddish-brown cross-bedded sandstone. Horizontal beds of varyingthicknessdivide themassintobandsoffrom25 to100feetin

thickness 300

4. Evenly beddedred sandstones; upperportionanindurated, darkreddish- brownstratum;induratedlayers alternatewithmorefriablelayersand

shalesbeneath 120

5.Massivegray sandstone, cross-bedded;upperportionisa light-graymassive friablebed. Theentiremassissubdividedinto six principalbedsby subhorizontallines ofbeddingofa dark,moreindurated sandstone. The bedsarefrom20to80feetin thickness,andmaybeseenonmanysteep

escarpmentsalong thecanon 810

6. Solid, partially cross-bedded sandstone, changing from gray to various

shadesofred 20

7. Evenly bedded,light-redsandstonewitha thin layerofintercalatedgray

sandstone 20

8. Dark-red sandstone; massivelayersalternatingwithshale,whichdisinte- gratesandforms a sloping talustothegray sandstonebeneath 180

9. Light-graysandstone 5

10.Beddedsandstoneofvariousshadesofredandgray. Thelayersofsand- stoneandtheirshaly partings areirregularin thickness. Scolithus bor- ingsoccur in greatnumbersinafriableyellowsandstone. Fragmentsof vegetablematterandcarbonizedwoodalsowereseen 230 11. Thinlayersofsandstone, alternatingwithbandsoffineargillaceous shale

holdingfishteethandshells 25

12. Massivelight-brown sandstone,brokenupintothick layers 50 13. Alternating layersofsandstoneandfineargillaceous shaleswithfishteeth,

etc 25

A

detailedsectionof13isas follows:

a.Lightsandylayerswithshaly partings 7 b.Fine, smooth, arenaceousandargillaceousshales,drabbrownto

redwithfilletsofgreen.

A

fewfishscaleswere found 6 c. Fine-gi'ained,light-coloredsandstone,2 to4feetinthickness 4

d. Sameas(b),onlymorefossiliferous 8

14. Reddish-brownfriablesandstone,brokeninto layers1to6 feetthick,with

shaly partings 120

15. Altcrnal:ingbandsofmarlsandshales,withlayersoffriable lightandred-

dish-brownsandstone 70

IG. Reddish-brownsandstonebrokenupinto layers2 to 7 feetinthicknesswith

a stratumofgray sandstone at the base 20

17. Arenaceous andearthy gypsiferousshales;marlites,purple,brown,bluish- green,andgreen,forminglow,roundedfoothillsandslopesfromthe Ver-

milioncliffstotheShinarumpconglomerate 650

18. Gray conglomerate andsandstone. Conglomerateformed of small, aga-

tizedpebbles andholdingsilicifiedwood 50

TotalofTriassic 2,845