dean fish, dinolestes lewini.

THE OSTEOLOGY AND RELATIONSHIP OF THE PERCOL DEAN FISH, DINOLESTES LEWINI.

By Edwin Chapin Starks,

AssisiantProfessorinthe Departmentof Biologyand _{Curator of}theMuseum, University of Washington,^Seattle, Washington.

As

a preliminaryto thispaper I willquotea paragraph, fromapa])er

by

Dr. TheodoreGill, "

On

the identityof

Esox

lewiniwith the Dino-

lestes millleri of Klnnzinger," published about twenty-five years ago in the

Annals and Magazine

of NaturalHistory. In it he gives the following concise history ofDinolestes:

In the tenthvolume ("the class Pisces") ofthe "Animal Kingdom" of Cuvier, edited byEdwardGriffith (1834),are a figure (plate60) anda brief notice(p.465) of a fishwhich has long been a puzzle to me. It is calledEsox lewini and ^only- noticedasfollows: "OurfigureofEsoxletviniisfromadrawingbyMr, Lewin,made

in

New

Holland, of a speciesnothitherto noticed." Itwasevident that the species thus named belonged neither to the genua-Esoxnoranywherenearit; and(1)the relationsofthefins, (2)the position of the ventralswithaspineand^fiverays each, (3)theformofthe head,and(4)the teeth indicatedforitaffinityto Chilodipterusand

alliedforms; but no first dorsal fin was represented. The question then arose whetherthatfinhadbeenatrophied(asinAspidophoroides,GoMopus,etc.) or(aswas more likely) had been overlooked. After nearly forty years the specieshasbeen recovered, andsingularlyenough,afterhaving escapedthe observation of thenum- erouscollectorsinthe Australian seas for solongatime,' hasinthesame yearbeen obtainedanddescribedbythreedifterentnaturalistsunderasmanynames,viz,Dino- lestesmillleriby Klunzinger, Neosphyrcena multiradiatabyCastelnau,and Lanioperca mordaxbyGiinther. There can benoquestionaboutatleastthe generic identity of theEsox lewiniwith the fishes described bythe threecontemporaries; anditnow appearsthat thefirstdorsalfinexists,butisquitesmall,andsustainedbyonly four orfivespines. KlunzingerandCastelnau referthetypetothefamilySphyrsenidse, andGiinther(withmorejustification I think) to the "Apogonina,"^i. e.,Chilodip- teridse.

This

work was

undertaken at Dr. Gill's suggestion in the hope of finding, inacomparative studyof the skeleton ofDinolesteswiththose of the Sphyrsenidse

and

the Cheilodipteridce,

some

characters that

'Itissaid,however,byCastelnautobecommon [atMelbourne]inthemonthsof May,June,andJuly; itattains2feetinlength. Thefishermencall it"Shij)Jack,"

butthatnameismoreparticularlyapplied to Temnodonsaltator.

Proceedings U. S. NationalMuseum, Vol. XXII-No. 1186.

Proc.N.

M.

vol. xxii 8 ¹¹³

114 PROCEEDINGS OF THE NATIONAL MUSEUM.

^vol.xxh.

would

decide the questionon whichtheauthorities disagreed, as

shown

inthelastsentence quotedfrom the abovepaper.

It

would

appear an easy matter to place this formunder one or the other of

two

familiesarranged in differentsuborders, asthe Sphyrsen- idse

and

Oheilodii^teridae usually are: but the fact that

two

of the authoritiesconsideritunder onefamily

and two

undertheother, indi- cates

how

^closetheresemblance

must

betoeither.

Sphyrmna

argenteaistheform chosen to represent the family Sphy-

rsenidse, while the only representativeprocurable of the Oheilodipter- idse

was Apogon

maculatiis.

The

skeleton of

Apogon was

foundtobe ofbutlittleassistanceinthis comparison.

Though

being undoubtedly Percoid, it differs as

much

fromDinolestes astheyboth differ fromthe

more

generalized Percoids, such ^as thebassor perch. Considering the difference betweenDino-

lestes

and Apogon

inexternalappearance,

we

have probablylittlereason to expect theinternal resemblanceto beotherwise. Perhapsif oneof the8p]iyrwna-]ikeOheilodipteroids could be

examined

there

would

be acloserresemblance.

To

besure Dinolestesdiffersfrom

Apogon

onlyin shape

and

compar- ative size of elements (that is, comparative between corresponding elements of each species),

and

notin arrangement,or lack or posses- sionof elements; but itis sovery differentin shape of cranium, form ofbody,

and

shape of fins that it would

seem

better to consider the Cheilodipteroid sideof the question partly

by

considering the Percoid fishes

more

orless as a whole.

Though,

of course, if it isijlaced with the Percoids it is onlyunder the familyOheilodipteridse, as the Per- coidsare

now

arranged, that Dinolestescould beadmitted.

Were

itnot that the ventrals oiDinolestesare apparentlythoracic,it

might appear aftera superficial externalexamination to be relatedto Sphyrcena.

The

long head, projecting lower jaw, fanglike teeth,

and

elongate preorbital region arevery Sphyrcenalike. Q'he shape of the

body and

dorsalfinsare alsosuggestive of that relationship.

Ininternalcharacters

we

findthat theethmoidiswide

and

flat,some-

what

overlying the

vomer and

prefrontalsinstead of being interposed between them. Tbisis the conditionfound in iSphyrcena.

The

nasals arevery

much

like thoseof Sphyrcena, being long

and

channeled

and

attached

by

^{their sides to} the ethmoidfor nearly theirwhole length.

This,however, is probably caused

by

the elongate snout,

and

goeswith

it as apartin keeping withthesurroundingconditions. Itdisposesof the characters

by

which analliance with Sphyrcena covtMbeproved.

Though

theshajDCofthe

body and

head, the canineteeth,

and

dorsal finsexhibitperhaps acloser superficialresemblanceto the Sphyraenidse than to theCheilodipteridiie, there areforms to be foundin thelatter family which approach this Sphyrcena-like appearance also. These characters therefore denote nothing in favor of either relationship.

The

charactersof theethmoid

and

nasals arethe only characterspos- sessed

by

Sphyrcenain

common

withDinolestesthat arenotalsoshared

NO.1186.

RELATIONSHIP OF DINOLESTES LEWINI—STAEES. 115

in

by members

^{of the family} Cheilodiptericlne.

They

are of uo great importance.

This, as has been said, is without considering the position of the ventrals.

As

thePercoidfishes

have

thoracic ventrals,

and

the

mem-

bers of the suborder Percesoces, under which the Sphyrtenidce is placed, have abdominal ventrals, it is cUfiQcult to see

how

Binolestes could

have

been thought to berelated to Sphyrcvna unless the ventrals were interpreted as being abnormally anterior abdominal ventrals.

The

ventrals,however, prove to be typical thoracic ventralswith the anterior point of the pelvic girdle interposed

and

attached between the opposing clavicles near their lower end above their symphysis.

Anterior abdominal ventralsmight

have

thepoint of the pelvicg-irdle touching* the clavicles or even extending slightly under them, but never interposedbetween them.

Another

character that refutesthe Sphyraenoid relationshipofI) ino- lestes is the lack of the long processes developed

backward

from the epiotics

and

supraoccipital crest, which are possessedin a greater or lessdegree

by

allthe Percesoces

and

reaches its greaterdevelopment in Sphyrcena.

A more

importantdifference is the structure ofthe teeth.

Though

bothBinolestes

and

Sphyrcena have large backward-directed canines, they are entirely different in the

way

in which they are attached to the bone of the jaw.

The

calcified tooth substance of the teeth of Binolestes reachesonly to the bone, whereit is anchylosedor so incor-

porated with the

bone

as to

make

^{itdifficult to} distinguish thelineof junction. This attachment is effected

by what Tomes

calls

"bone

of attachment."

A

substance resemblingcement,butunlike true cement,

isdeveloped from theperiosteum rather than fromthe dentalcapsule.

Such

teeth

may

be developed from sockets, but as the calcified tooth substanceisjjushed out the cavitybehind fillswith theboneofattach-

ment and

becomes obliterated.

The

dentine never extends into a cavity of the

bone

in the

mature

tooth. This isa Percoid character.

The

teeth of Sphyrcena,on the other hand, areset in sockets.

The

attachmentof teeth in alveoliisof such rareoccurrence

among

fishes

and must

be sodeepseated that

we

canhardlyinterpret itas lessthan a family character. Mr.

W.

G-.Eidewood, in a paper,'has this to say inregardto this class of teeth

:

Thetoothandboneareinorganic continuityby meansof a periosteal layercom-

mon

tothetooth and the jaw; and this layermayremain nncalcified so that the teethcanbepulled out oftheir sockets, as in some Caracinoidfishes; or"boneof attachment" may,except in young teeth, anchylose the tooth to thewall of the socket, e.g,, Sphyriena.

But

whether ornot the tooth

becomes

cemented in, the enamel

and

dentine extendintoa cavity

and

do not

become

incorporated with the bone.

'Natural Science, YIII, June, 1896,p. 383.

116 FEOCEEDINGS OF THE NATIONAL MUSEUM.

Thereis also adifference inthe shapeof the teeth of

Sphyrwna and

Dinolestes.

Those

of the former are laucelike

—

^{that is, compressed}

laterally

and

with cutting edges. Those of the latter are round in transverse section.

The

vertebrae ofDinolestes aretypical, oriu general resembling the Percoids

and most bouy

fishes iuthattheyare of moderatelength

and

not

much

constricted inthe middle.

They

have parapophyses devel- oped behindthe fourth vertebra,

two

pitsonthe sideof each vertebra separated

by

a longitudinalridge,

and

theabdominalvertebraj with a piton the ventralsidewith ridgeson each sideof it.

The

vertebraeof Sphyraina are long

and

smooth with scarcely

any

pits,

much

constricted in the middle,

making them

hourglass sliaped,

and

^{with only} one or

two

pairs of parapophyses.

The

shape of thecranium of ^Dinolestes isalso

more

typicallyPercoid in appearance than SphyrfFuoid with ^the slightly rising supraoccipital crest

and more

wedge-shapedlateralview.

A

recapitulation with these points condensed will

show

atoncethe aflBnityof Dinolestes tothe Cheilodipterid?e.

1.

The

Percoid appearingcranium.

2.

The

thoracic ventrals.

3.

The

anchylosed teethratherthanteeth in sockets.

4.

The

character of the vertebrii^, typical; not specialized as in Spliyrcvna.

5.

The

lack of the longposterior i)rocesses fromtheepiotics.

Theseconclusions arefortified

by

the followingdescription.

DINOLESTES LEWINI.

Esox lewini Griffith (?), Cuvier's Animal Kingdom, Griffith eel.,

X

(1834), p.46,5,pi.60.

Dinolestes miiUeriKlunzinger,ArcliivfiirNat.,38. Jahrg.1(1872), p. 30;Hobson Bay, SouthAustralia.

Neosphyrwna muUiradiata Castelnau, Proc. Zool.and Acclim.Soc. Victoria, I (1872), p. 96; Melbourne.

LaiHopercamordaxGunther, Ann. andMag.Nat.Hist.,4thser., X, (September, 1872), p.183; Tasmania.

DinoJesies lewiniGill,Ann.andMag. Nat.Hist.,4thser.,

XIV

(1874), p.160.

DIAGNOSIS.

Body

rather elongate_; preorbitalregionproduced;

mouth

large, the lower

jaw

projecting; canine teeth on lower

jaw

posteriorly

and

on premaxillaries at their symphysis; sharp, cardiform teeth in asingle

row

on jaws,

vomer and

palatines; an inner

row

of villiformteeth

on

premaxillaries; three toothed superiorpharyngeals;lowerpharyngeals rather narrow, separate_j gillrakers long

and

slender, about 4

+

¹³⁵

opercles without spines or ridges; branchiostegals 7; maxillary with supplementalbone; nasalselongate, attached

by

their sidesfor nearly theirwholelength; parietals separated; ethmoid

somewhat

^overlying prefrontals

and vomer

_j posttemporal forked; postclavicle of

two

parts;

NO.1186.

BEL A TIONSHIP OF DINOLESTES LE WINI—STARKS. 117

basispheuoid with, a descendiug process;

myodome

present with a small pore to the exterior posteriorly; no suborbital shelf; vertebrae 27; parapophyses present on all abdominal vertebnie except first 3;

scales cycloid; maxillaries,cheeks,opercles,

and

lower

jaw

with scales;

lateral line straight, ranning well out on base of caudal, scales along

itscourse systematicallycrowded; baseof anal, softdorsal,

and

caudal withsmallscales; analwith2 spines

and

about25 rays; dorsals remote, thefirstof about 5 slender spines, the second with 1 spine

and

about 18 rays; ventrals with1 spine

aud

5 rays each; interspinous bonesnot extending between^{vertebral spines.}

OSTEOLOGY.

Cranium, as viewed from above,ratherelongate

and

narrow. Inter- orbitalregiona flattish area withthe sides nearly parallel the greater part of its length, occupying at least a third of length of cranium.

Preorbital region elongate, not tapering till near end, occupying another third of length of cranium. Region surrounding foramen

magnum

slightlyproduced. Lateral view of

cranium

taj)eringrather regularlytovomer.

Supraoccipital interposed betweenexoccipitals nearlyto their poste- rior ends; its crest developed superiorly

and

posteriorly, scarcely extendingpastexoccipitalsiDosteriorly.

Exoccipitalsbroadly meeting above basioccii^ital, entirely surround- ing foramen

magnum.

Parietals widely separated

by

supraoccipital, not extending over epiotics.

Bpiotics with scarcely

any

process.

Prootics, opisthotics, sphenotics,

and

pterotics typical; that is,

Percoid-like.

Alispheuoids widely separated.

The

anterior opening into brain caselarge.

Basispheuoid present; a foramen between it

and

basis crauii.

A

slenderprocess descendingfrom ^it

and

attached toparasphenoid,

Myodome

present; opening to the exterior at its posterior end through an extremely smallforamen.

Parasphenoid spreadingout wide])osteriorly.

Vomer

bearing sharp short teeth ina single

row

around its anterior edges. Teeth

becoming

smaller anteriorly.

Prefrontals large

and

rather elongate,theolfactoryforamen scarcely behindmiddle.

Ethmoid

entirely superior to prefrontals

aud

vomer, widely ^overly- ing

them aud

extending to edge of rostrum,

A

raised area alongits middle.

Nasalsthin elongate rods ofbone attached

by

their sides to ethmoid for nearly their whole length; their length over a fourth that of cranium.

Preorbital longer than wide; itsoutline triangular.

118 PROCEEDINGS OF THE NATIONAL MUSEUM.

^vouxxii.

Suborbital ring of the usual

number

of five bones with a sensory canalthroughthem.

No

suborbitalshelf.^

Operclewithout ridges or spines on outer surface.

On

inner sur- face a sharp horizontal ridge runs posteriorly from its condyle with hyomandibular.

Subopercle extending around lower corner of opercle,

upward and

backward, forminglower part of posterioropercular angle.

Intero])ercleverybroadly attachedtosubopercleatitsupperposterior side.

Preopercle with ridge

and

sensory canalas usual.

Lower

limb of hyomandibularratherlong and rod-like.

Palato-pterygoid processvery^long

and

stout.

A

^single

^row

^{of small}

teeth along lower edge extending ^anteriorly

upon

a process

beyond main

partof palatine

somewhat

similar tothe usual processfromupjier edge ^of that bone. Suspensoriumotherwisetypical.

Lower jaw heavy and

^long.

The

articular half as wide as long.

Teeth in a single

row upon

dentary, three or four canines present posteriorly.

Angular

present, rather small.

Maxillarywithlongsupplemental

bone

along posterioredge.

Premaxillary rather slender,

much

widened at middle into a wide process which extends behind maxillary; its lower end very slender.

A

^single

^row

^of elongate pointed or smallcanine teethalong its edge, largest medially, growing gradually smaller toward each end. Inside of this

row

a villiform band, widest medially.

At

upper

end

of each maxillary aretwo large canines anchylosed immovably, the posterior pair

much hooked

back.

Clavicle

and

hypercoracoid typical, oras in the Percoids.

Hypocoracoid as usual broadly joined at upper end to clavicle

and

hypercoracoid, thence arching

away and

touchinglower

end

ofclavicle againwith a rather slenderi^rocess. Besidesthis,from itsmiddle, run- ningthrough the usual interspace between it

and

clavicle,is another processflat

and

thin, but strengthened through^its middle, reachingto

and

joinedtoclavicle.

Actiuosts four,rather short.

Pectoral not nearerupjDcrendofclaviclethanisusualinthe Percoids,

its upper ray working directly

upon

hypercoracoid, Postclavicle in

two

parts, theinferiorverylong.

Supraclavicle ofmoderatelength.

Post-temporal widelyforked; its articulationwith skull typical.

Inferior hypohyal scarcely visible on outer surface of hyoid ^arch, being covered

by

superior hypohyal, which forms the greater part of frontof arch.

Hypohyals

ofabout equal sizeoninner surface of arch.

Ceratohyals, ephyals,

and

interhyals typical.

'Suborbitalshelf: a small sbelf of bone extending inward from the suborbital ring and conforming to the rotundity of the eyeball. Possessed by many ofthe higherbonyiishes.

NO.1186.

BELA TIONSniP OF DINOLESTES LE WINI—STABKS. 119

Branchiostegals seven, fourbeing borne

by

ceratohyal

and

three

by

epiliyal; tlie tliree anterior ones attached to inner surface of byoid arch,

Glossohyal wide, flat, or slightlyconcaveabove.

Urohyal elongate, thin, without doubleheelbelow, exceptatextreme anteriorend.

Basibranchials three

—

^{the first} not supporting

any

arch, thesecond supporting thefirst arch,

and

to thethirdthesecond

and

third arches arejoined.

Ko

ossifiedbasibranchialtofourth arch.

Epibranchials of third arch

meet

behind last basibranchial; epi- branchials of fourtharchabsent.

Suspensory pharyngeals presentonfirstarch.

Superiorpharyngealsthree innumber,thatis, on second, third,

and

fourth arches; the secondlargest,

and

withthe thirdforming

an

elon- gatepatch.

JFirst

two

interspinalrays of dorsal

and

ofanal notcoalesced.

None

of theinterspinals interposedbetween neuralorh?emal spines.

The

interval betweenfirst

and

second dorsals occupied

by two

free auxiliaryiuterneural spines.

Firstinterhaemal spinenotenlargedor in

any way

differentiatedfrom

itsfellows. Interhsemals equallygraduated from behind forward.

Ventral fins trulythoracic.

The

pelvic girdlelong

and

taperingtoa slender point, which is interi^osed between the clavicles above their union.

The

vertebral

column composed

of 10 abdominal

and

16 caudal, which, withtheusual hypural,

number

27 vertebrne.

Superior zygapophyses bothposteriorly

and

anteriorly present,but small, as isusualinthePercoid fishes.

Inferior zygapophyses well developedposteriorlynearmiddle ofcol-

umn

; anteriorly scarcelydiscernible.

Parapophyses developed onfourth

and

succeeding abdominalverte-

briie, growing larger posteriorly; the last pair connected near their bases

by

abridge of bone.

Hypural

assisted in supporting caudalfin

by

spines from,

two

preced- ingvertebrae.

Kibs

and

ei)ipleurals typical.

120 PROCEEDINGS OF TRE NATIONAL MUSEUM.

^vol.xxii.

EXPLANATION OF

PLATES.

[Drawn byChloeLesleyStarks.]

Plates VIII, IX, and X, superior, lateral, and posterior views ofthe craniumof Dinolesteslewini,slseletonNo.47877, U.S.N.M.,from PortJaclsson,Australia.

Plate XI,Dinolesteslewini,No.47929, U.S.N.M.,from Tasmania.

SIGNIFICANCE OF REFERENCE LETTERS USED ON PLATES.

als. Alispbehoid. jp. Parietal

has. Basisphenoid. pas. Parasphenoid.

io. Basioccipital. pf. Prefrontal.

e. Ethmoid. pro. Prootic.

eo. Exoccipital. pto. Pterotic.

epo. Epiotic. so. Supraoccipital.

/>•-. Frontal. spo. Sphenotic.

opo. Opisthotic. V. Vomer.

U.S. NATIONAL MUSEUM PROCEEDINGS, VOL XXII PL.VII!

Superior View ofCranium of Dinolestes lewini.

For explanation of plateseepage120.

U.S. NATIONALMUSEUM PROCEEDINGS, VOL. XXII PL. IX

'fux^

Lateral View of Cranium of Dinolesteslewini.

For explanation of plateseepage120.

U.S. NATIONALMUSEUM PROCEEDINGS, VOL. XXII PL. X

iuQ SMjO

Posterior Viewof Cranium of Dinolestes lewini.

For fxplanation of plateseepage120.

U. S. NATIONAL MUSEUM PROCEEDINGS, VOL. XXII PL. XI

Q

i

1